Hi, Sewil, welcome to iPF!
It would be easier for members to help you, if you provide more information: which iPad do you own (1-4, Air, mini, mini retina), is your software up to date, or is your device jailbroken, what else you consider to be important for us to know.
For a start, you can try the usual fixes:
Reset your device: press and hold Home and Power button at the same time until the Apple logo appears, then release both and let the iPad power up.
Restart it: turn off your device, wait for a few minutes, then turn it on again.
Force close apps (crashing is often caused by too many of them running/open):
iOS6: double tap Home button to reveal multitask bar, then tap one of the icons there until they start to wiggle. Delete them by pressing the x.
iOS 7: also double tap Home button, then swipe thumbnails above the app icons towards the top of the screen.