You missed the big class update. It's pretty substantial.
Class features have been spread out over more levels. Level 1 characters only get one or two class features with few or no choices, emphasizing quick character creation. Other important class features show up over the next few levels (e.g., Paladins get divine sense at level 1, spellcasting at level 2, turn undead at level 3...). You pick a subclass around level 3, and you get your first ability score improvement (or, optionally, feat) around level 4.