You can look at typically what they do coming out of the openings you play to understand the plans and how they execute. But first step would be to know your opening and middle game ideas else gonna be hard.
How would I would go about reviewing grandmaster games

Pick a grandmaster game and pick a side.
What would you play? What did the grandmaster play? Which is better? Why?
Go to the next move.

Hi!
I think you already have reached a decent level of play and need to go into the details and subtleties of the game to get better. For that it is best to work with an expert player /teacher /coach that would customize the explanations and make best of your time and effort invested. This applies to all the aspects of chess but especially to analyzing games -either master games or your own games.
I wrote a post on chess improvement, you could check it out if interested: https://www.chess.com/blog/maafernan/chess-skills-development
Good luck!

A couple of good annotated game books suitable for your level are:
- Neil McDonald - The Art of Logical Thinking
- Sunil Weeramantry - Best Lessons of a Chess Coach
Both of these books feature exciting games with good commentary.
If you want to cover a large number of GM games, some more advanced books are:
- Mammoth Book of the World's Greatest Chess Games
- Kasparov's My Great Predecessors series
- Bobby Fischer's My 60 Memorable Games
Those books are generally recommended for about 1800 or 1900 level, but you may still find them useful.
You can also learn quite a bit by watching videos where strong players analyze GM games. Some examples are Kingscrusher, Daniel King, Hanging Pawns, Agadmator, Naroditsky, Saint Louis Chess Club, Gotham Chess, Ginger GM.
We are spoiled for choice.
So im trying to grow my rating and I don't know how to review grandmaster games