Some threads, like the 30-30 just won't die...
As for me I think a lever gun w/o scope, a .22LR w/o scope, a shotgun w/o scope, and a handgun w/o scope to be 'nearly' required first guns to own.
Guess what? They are the most affordable to get into and then run, with cheap ammo practically everywhere. Get good with those and you can handle 90+ percent of all fire arm tasks.
After that it is wide open what do you like? Me I would say a scoped .308, .223 with or w/o scope, perhaps an AK variant? A magnum, a big bore, or an AR? All are a kick and loads of fun, in fact so many manufactures, types, and calibers that it is all almost impossible to select the next... but damn if it isn't gas trying.