As it stands right now, you won't run into a thargoid unless you drop into the random signal sites. So you have to purposely go look for them, and you have to have a ship that is equipped to handle or take a beating from thargoids if you want to survive one. Personally, I have not encountered any nor have I attempted to fight any, too busy doing other stuff to worry about them.
There also have been a couple trips where I died before turning in the exploration data, fortunately I have Cpts Log which I use to track where I have made first discoveries, just dust off the ship and remake the trip, making sure I hit all the prior first discovery systems as well as finding new ones along the way.
I do my own thing in Elite Dangerous and am content with that, the only time I stay in Open is when I am out exploring, before returning I drop into a private group so the only griefers I may encounter are NPCs and they are easy to avoid. I don't play this game to be someone else's content, I play it for my enjoyment and I get no thrill out of taking on another "Commander". I have nothing to prove to anyone so therefore I don't need to fight someone else just to feel good about myself. There are formats for that i.e. in Arena or the PVP League.