I'd be quite happy to fly around totally unarmed but that might be a bit risky.
Sorry, incoming essay

Don't carry cargo in your exploration ship and in game NPC (Non-Player Character) pirates might interdict you (which you can easily evade once you know how in your super light nimble exploration ship), but after a scan will leave you alone. Always play in Solo, especially when returning from a long voyage with lots of exploration data to sell, and no player can attack you. Serious exploration ships do not have guns - that just adds weight and reduces jump range. Maybe a mining laser just in case you need to get some raw materials like iron and nickel while you are out, but I just stock up with those before I leave. The SRV can be used to collect materials on planet surfaces anyway.
If you did get attacked, keep running, hope your shields hold out, plot a course to somewhere 100ly away. Your highly engineered for jump range exploration ship can jump so far no combat ship can follow you. If you are in a Krait Phantom and get attacked by another Phantom, it's weapons and heavier power plant to power them will make it heavier than your ship and it will have a lower jump range.
So what ship have you finished up with? Your Galaxy exploration ship? 
I have a Krait Phantom engineered as much as it is possible to engineer it. There are ways I could reduce the weight further and increase the jump range, but I have a few other design parameters that added weight.
One time, after landing on several low gravity moons to collect materials as shown in that "materials gathering" video, I decided on a whim to land on another planet I found. I was in a low gravity body mindset, powered toward the ground to land faster, realised I was not stopping, bounced off the ground with no shields left and only 16% hull strength remaining and had just enough time to think, "no problem, I have a repair limpet controller on board to fix the hull and the shields will recover". I could not stop the ship hitting the ground again - boom!
So my ship now has 5D shields engineered with grade 5 enhanced lower power with lo draw special effect and 3 x light weight 0E shield boosters with heavy duty grade 5 and supercapacitors. This gives me 662MJ of shield strength with low power consumption which I can run off a 3A power plant with grade 1 low emissions with thermal spread special effect. I tested this shield set up by deliberately flying into the surface of a 6G planet, where the ship skipped across the ground like a flat stone on water before I pulled up with no shields and 35% hull left. Success - the ship survived. The armour is also engineered heavy duty 5 + deep plate, and it took a long time to access engineers to get that done.
The power plant is A grade small and light weight and means the ship runs very cool, sometimes with only 18% heat. I am told anything under 20% and it makes it hard for other ships to scan you and get a weapons lock - stealth! The other benefit is the ship stays cool while fuel scooping and you can start charging the FSD (which creates a lot of heat) sooner while still closer to the star.
I have 2 SRVs so I can take risks and have fun in the SRV sometimes not worrying about destroying it. The AFMU repairs the FSD and required if you are using neutron stars to supercharge your FSD. This multiplies your jump range by 4 for one jump which is up to 282 light years for me. Your FSD takes 1% to 2% damage with each boosted jump and its best to repair it when it gets down to 80%. 78% and you start to see FSD malfunction warnings.
Materials allow you to synthesis repairs, fuel and ammo for SRVs, the AFMU etc.
The light weight 3D power distributor is engineered grade 5 engine focus + charge enhanced to get the capacity to boost on what would otherwise be an under powered distributor. This with the 4D thrusters dirty grade 5 + drag engineered makes the ship quite fast and allows it to easily escape from high G planets. This power distributor would not do well powering weapons, but... exploration ship - no weapons. Tip: Set maximum pips to engines, the rest to SYS, nothing on weapons and then power down the power distributor. It only needs to be powered to change where the pips (energy) is focused - which you never need to change on an exploration ship.
Note items in grey are powered off most of the time. The AFMU is power hungry, but you don't use it at the same tie as having the FSD powered, so you manage what is turned on and off to stay inside the limits of your small power plant which keeps down the weight and keeps up the jump range. The rest of the engineering is for light weight.
Here's the build:
https://s.orbis.zone/gfre
If my sales pitch for the Phantom is not quite enough to convince you, watch this from The Pilot who is also an explorer at heart:
Source: https://www.youtube.com/watch?v=aLgYskzDU5o
Every explorer must own this ship at least for a while - as soon as you have the credits which will be about 10 stops on the road to riches using the Hauler - which overheats very easily when fuel scooping - don't let that put you off fuel scooping. The DBX and all these other ships stay much cooler when scooping:
Source: https://www.youtube.com/watch?v=1XkAFcQ3YKk
The ASP Explorer is also a legend - if you never descend to planet surfaces, you could fly without shields, shield boosters and SRV bays, at which point the ASP Explorer has space for everything you need for a lot less money than the Phantom. I don't use the ASP X because I cannot fit in 2 SRVs or supercruise assist and I cannot get the shields up to the strength I want. It's not a deal breaker, but I don't like the WW1 bi-plane thruster noise this ship has. If you can live with a single SRV, no supercruise assist and weaker or no shields, the ASP X will get you anywhere in the galaxy you want to go sooner:
Source: https://www.youtube.com/watch?v=v6D0aXjkQ8A
The Anaconda is expensive and slow to turn in supercruise and you do a lot of turning in supercruise while exploring. But you can carry a ship launch fighter which can be fun to fly when your are in the middle of nowhere.
Source: https://www.youtube.com/watch?v=lCdbkzyJhas
A tip: Download EDDiscovery (for PC users), connect it up to
https://www.edsm.net/ and then look back at where you have been:
Source: https://i.imgur.com/5PN26XN.jpg