problem to start up my iPad

I would restore it

https://discussions.apple.com/thread/5269891

What iPad year and model do you own?

Have you tried a simple hard reset of your iPad by holding down both the Home and sleep/wake buttons simultaneously until your iPad goes to black and restarts with Apple logo, then release the buttons?

If your iPad id frozen or unresponsive, follow this:

https://support.apple.com/HT201412