Want to learn. I want to do human figure sketching and draw buildings.

So i know there are tons of content out there to start but should i know any basic exercises that i should be really good at before i can get into any of those. And i do a little bit of gesture sketching whenever i get time, so can someone tell me what do i do next, as in what is the next exercise i should practice and next after that? Your help is greatly appreciated.