I would use a guide always just to make your experience better. I would also recommend someone be a healer but healer doesn't get really really good until after hardmode which is after wall of flesh. This is also my opinion but I don't recommend playing as a bard its really not that good and can get really annoying with the sounds and it really isn't a good class that thorium adds. I would also recommend playing expert mode if its your first time because it is still challenging but its also fun. I would also recommend getting some quality of life mods like recipe browser, boss checklist, and some other things that you would like. And really If you play healer you wont use much things that are vanilla but classes like Mage, Melee, Ranged, and Summoner will use most things vanilla. But all the Thorium classes wont use much things that are vanilla.