No issues with this
Basically you are just choosing to not use one of the best features of your race. An Aarakocra without flight is a very underpowered race, but if you are ok with that there is no need to homebrew anything to make this work.
Replace flight with a feat
In campaign 2 of High Rollers (a D&D livestream) one of the players choose to play a flightless Aarakocra. The DM Mark Hulmes allowed the player to replace flight with a free feat instead. This returns the Aarakocra to being possibly the strongest race you can choose, but not in such a gamebreak way as a 50ft fly speed.
It is important to note that the character has story reasons for being flightless (an accident took his wing) and that not all Aarakocra in this world are flightless. Additionally the player makes sub-optimal choices for roleplaying reasons which prevents this character from being too powerful. It is possible that with a player more focused on optimization this house-rule would become unbalanced.