I've seen some good flowchart style progression guides in the past but can't seem to find them anymore. Having been shown EVE online once I kind of know what you might mean. So what I'd say is that there are 3 main categories of ships. Every ship can perform every task but to varying degrees of success.
Cargo haulers have good qualities like cargo space, jump range and being generally cheaper than a multirole equivalent. They normally have bad offensive capabilities and bad maneuverability. In order they are: Hauler, Type-6, Keelback, Type-7 and Type-9.
Multirole ships are the in between of cargo and combat. Generally more expensive per ton of cargo capacity but they'll be more maneuverable and can even be used as a fighter. They are: Adder, Cobra MkIII, Cobra MkIV(not available to all), Diamondback Scout, Diamondback Explorer, Asp Scout, Asp Explorer, Python and Anaconda.
Combat ships are fast, offensive ships that for size and price generally can't carry much cargo or jump very far. They are: Eagle, Viper MkIII, Viper MkIV, Vulture and Fer-de-lance.
There are also Passenger ships that are really cargo haulers but are the only ships that can carry Luxury cabins. Personally I've found that running an economy liner in a multirole ship is more profitable but if you dream of being a cruise liner pilot of the stars then in order they go: Dolphin, Orca and Beluga.
Faction specific ships that require a large grind to unlock are as follows. Imperial ships: Imperial Eagle, Imperial Courier, Imperial Clipper and Imperial Cutter. Federal ships: Federal Dropship, Federal Assault Ship, Federal Gunship and Federal Corvette. Being a fed player I don't claim to know much about the Imperial ships but the Cutter does have the highest cargo capacity in game and can stock the largest shields. Federal ships are definitely combat focused with the Corvette (in my opinion) being the best combat ship in the game. It's the most nimble (not fastest but maneuverable) of the larger ships and can stock two huge weapons as opposed to one like other large ships.
The top quality of an explorer is jump range so I recommend the Diamondback Explorer, Asp Explorer and the Anaconda. You'll need an advanced discovery scanner, detailed surface scanner and fuel scoop minimum to really explore profitably.
Ships progression isn't linear and upgrading a lower ship can sometimes be better than buying the next. Some can be skipped altogether. Remember to always keep money for rebuy when you are upgrading and ditch that sidewinder as soon as you can afford to safely.
As for corporations, we have the three superpowers that I touched on already. The Federation, Empire and Alliance. Reputation can be increased with all three but ranks and ships are only currently available for Federation and Empire (Alliance are due to get something similar next year). There are also several independent powers if you want something more niche like a pirate guild or utopian cult.
I run a player group so I'm always going to say join a group but to be honest I also soloed the first 500 hours of this game. If you want to do combat or faction building then these activities are best done in a group. Trading and exploring are kind of lone wolf professions but don't feel like you can't join groups if you'd like company. Trading can be greatly beneficial to faction building and even explorers can sell data to specific stations to assist a group. Plus it can get lonely out there so having a Discord to chat to other players can really help in this game.
Anyway, think I covered all the ships and stuff. Welcome to the community everyone.
