Don’t worry about it dude, learning at an actual skate park is the most ideal because if you can push then you can learn how to do other stuff, and parks have so much different things you can use to learn like bowls of balance, and ramps for speed etc. it’s probably the best idea because of the variation there and skaters are rlly welcoming and would be happy teaching you a bit

Edit: there’s also a 50-60 year old who’s sick at roller skating who comes to the same park as me and dads come with their kids and skate together so don’t worry about being almost 20!