Hi Hasseman92,
May I suggest that the most pressing question isn't "What?". but "When?"
Scheduling a time that is dedicated to Poker study will make that study time more effective than just randomly deciding, "Oh, I'll study poker a bit now".
On to what...
If you haven't done so already, go though the "No Limit Hold'em lessons overview".
Next: How...
Go through each article thoroughly. Rather than just reading them, work the examples until you understand them.
Following your study session, play a couple of hundred hands looking for spots to apply what you just learned. Even if you are on higher limits, 1-tabling NL2 Fast-Fold lets you do this at low cost, and fairly quickly.
I always seem to forget that a lot of people like Sit-and-Go tournaments. If that's your thing, there is a SNG lesson overview also.
Don't forget the live coaching sessions.
Follow the forum thread https://forums.pokerstrategy.com/forum/thread.php?threadid=401699&goto=firstnew to keep informed of the upcoming sessions.
Be sure to follow to the PokerStrategy.com twitch channel
There are also videos, many of which are recorded coaching sessions. Use the "search" drop-down to make it easier to find ones that interest you...
All the best,
VS