First of all you have see if you have filled all the required information needed such as your bio, profile image, city, etc. After that comes who you are following and who following you back.
There is no point following a people who are not following you back unless he is something who adding value to your timeline. You should unfollow all those people who are not following you back are inactive. Instead follow people are active and tweet regularly and most important they are in your niche. Here are six free twitter unfollow tools that you can use to mass unfollow non followers.
https://curiousblogger.com/twitter-unfollow-tools/.