I am a college football player, I have been playing football since young age but I am not doing any kind of squat or strength exercises because whenever I do I become immobile for 15 min. So if you can please suggest me some exercises and something that can help. I dont think that only sprinting will help my football
Can you define "immobile"? If you have an injury or condition you need to address that first. Otherwise Squats are a really technical exercise if you want to do them right. Most people have to start with a lot of flexibility and technique work before they can get serious.
Stretching your hamstrings, gluts, quads and ankles is probably where you need to start, unless there is an underlying medical condition causing you to tighten up.
How old are you?