Question - how to start learning to make midgame plays after a typical opening?

I have a few openings that happen nearly every game, but around 10+ moves things start to stray to strategy that I have to come up with on the fly as I have not studied midgame or anything of that sort. I understand basic chess strategy but I am wondering if anyone has any pointers or resources for structuring a longer attack that may be more involved than a two move attack? Thanks in advance

Study common pawn structures (isolated queen's pawn, doubled pawns, pawn chains) and the typical plans associated with them.

I dont have a full list for possible plans, but some of the most typical questions are probably:

- Are you yourself under attack ? Do you move the attacked piece away, do you defend it, do you block the attack, or you answer with an equal or greater thread ?

- Are there tactical opportunities available ? Like, has the opponent blundered ?

- How safe is the opponent king ? Can one amass pieces towards the king, to prepare for an attack ?

- What weaknesses does the opponent have ? Can you maybe force new such weaknesses, or make them worse ? Can you accumulate attacks on these weaknesses ?

- Can you improve the positions of your pieces ? Are there great outposts for your knights ? Are there good diagonals for your bishops ? Are there open files for your rooks ? How can you make sure such positions arent challenged by the opponent ?

- Do you have bad pieces that you can trade for good pieces of the opponent ?

Study annotated grandmaster games.

After the end of my opening knowledge, what I usually do is :
- Move pieces to better squares (with thinking about the activity of pieces and strategy)
- I look at the position and think about how I can attack afterwards. (only when I'm safe)
- I check if my opponent has a tactical chance to attack me, and if so, I block it.
- I try to control the situation, not passively deal with my opponent's movements.

If you have a main opening, look at master games or stats to see which ideas work best. It will help you understand that opening further, and make it easy to find a right strategy.

A really good video about how to play the middlegame is by the way this one:

https://www.youtube.com/watch?v=r6Uea1_jnVo

Its from a CM (candidate master), so "only" Elo 2200, which actually means he has more "connection" and is easier to understand for us regular chessplayers, and he picked a really good example position and really typical moves to explain the concepts.