When I clean or clear my apps will I lose the app itself or just the data I have in it?
What do you mean by 'clean and clear'? You won't lose anything by clearing the app cache.
Like jrh4054 said that if you clear cache you will not lose the app. If you clear the clear data one it will remove all the info the app has collected since you turned the phone on. but doing that will not take the app off your phone.