How old is your iPad? Apple slows down older ones to entice you to replace. But they say its a feature.
I would start with clearing the cache, and reboot after that. Location services is another feature that you might want to turn off (sucks up battery power and slows the system down slightly).
The newer updates don’t work well with older iPads.
Go to the App Store. Install ghostery.
It will block most of the trackers, ads and other crap that comes with most websites these days. Avoiding the additional downloaded garbage will free up resources like memory, processing capability, etc and allow you to see more web content without the pages continually reloading.
Be sure to select the option to block all trackers in ghostery.
Opera is a browser you can try, stay away from Chrome.
Turn off your iPad and turn it back on.
Make sure you have the latest update too.
Turn off java script. Turn it back on when necessary.
Hold down the round button and the power button at the same time until you see an arrow on the screen (5 to 10 seconds). Swipe the arrow.
Just hitting the power button puts it to sleep. This does an actual reboot.