My iPhone 4S keeps freezing. What do I do?

My iPhone 4S keeps freezing up or apps crashing. What do I do? I am so not tech smart.It'd be great if someone could help! :)

Buy a new one.

Try keeping it off for a little bit
Are you low on memory? Try deleting a few things

Same things going on with me with the 4s and now my phone wont even turn on, take it to apple and see what they say thats the best bet if they dont do anything about it sell the phone and get android apple blows.