I had the same problem when I started studying,
The first thing is, dont focus on freerolls even if you play them the majority of the time (which is what I do, due to the lack of time I have).
Strategies for MTTs is what we need to focus, because applying the basics IS having a freeroll strategy = play sound basic mtt poker.
Basic MTT strategy:
1 - Learn about the different phases of the tournament:
- There are early stages, mid and late. You need to adjust your game based on it for the next steps.
2 - Learn about Opening Ranges:
- In the beginning, it was terrible for me to understand. But, thinking ranges make you start your game better.
- Ranges are based on positions. There are variables that will make you change your flop approach depending on the villains actions pre-flop. That helps a lot.
- Stack based ranges (needed to adapt during the different tournament stages).
Now you have two basic steps to start your studies:
- MTT structure and how to apply your starting ranges there.
I am assuming that you are very new to MTTs, so that is my suggestion where to start.
From this point, you can start gathering more info on it to study. Like I said, playing sound basic poke in freerolls puts you ahead on the game but it wont make you win.
Then, after being used to ranges you will have a base to improve your flop plays and more complex situations. It is basically being patient. Studying the situations that happens the most with you and definitely review hands that you felt uncomfortable playing or did not know how to play.
Hope it helps, I was completely lost when I get back on playing online.