It's a nice entry. And it's very good for the first game ever. Now you have experience how to make a game I encourage you to take a look at free game templates of fps game like https://assetstore.unity.com/packages/templates/unity-learn-fps-microgame-urp-15... this one or even more advanced like this one https://assetstore.unity.com/packages/templates/systems/low-poly-shooter-pack-fr... you can use their code to make you game even more interesting. I think it will be good to have in-game menu, autosave, a bit work on character sounds will be great. Unity has problem of playing multiple sounds together it can slow down system pretty bad be careful with them.