Just what I found works best!
Personally I enjoy flying Astero. Not the cheapest thing to have but if one’s careful enough, it can gtfo very fast, is durable and thus can handle many LS combat sites and overall is very versatile. Add a friend or corpmate and DED 5/10 becomes bread and butter.
As far as income goes, selling data/relic, personal effects, drone parts or deadspace modules can yield solid isk. Question is, do you need billion to do what you enjoy? Frigates are cheap and solid. Fun is doing most with the least.