What top laner should I try after Yorick?

Garen is a nice next pick if you want a straightforward kit while learning lane basics. You can spend more attention on minions, trades, and the map instead of managing lots of abilities. Give him a few games and see if his direct style suits you.

If you want to try a tankier role, Malphite is a different kind of top laner to learn. He gives you practice thinking about when to start a fight and how to help your team, rather than focusing mostly on pushing. He may feel pretty different from Yorick, which can be useful.

If what you enjoy is a patient, steady push, Nasus could be worth a look. He has a different feel from Yorick, but lets you practice choosing when to farm safely and when to challenge your opponent. No need to rush into a big champion pool, though.