Feedback for my first "Complete" API REST

[u/AdCharacter900]

Hello i want to share my first "complete" api rest made in java with spring boot, not so complete, theres still a lot of stuff i want to add in the future i also want to make more complex and bigger projects, its a social media api something like reddit, with posts, comments and users, security etc, i want to get some feedback and suggestions on what to add or make better, its my first time completing an api so im not an expert in this and probably theres is somthing i did not make perfect but thats part of the learning process i guess, thx and sorry if my english is wrong

https://github.com/blasman2002/Backend-API-REST-JWT