is there a quicker way to pair roku remote to tv?

Can't see a pairing button under the battery cover? Then it's the basic infrared kind, nothing to pair. If it's not working, swap the batteries and make sure nothing is blocking the front of the box. For the other kind there's also Settings > Remotes & devices > Pair new device. Use the Roku phone app to get there if the remote is useless.

Depends which remote you have. The basic ones are infrared and don't pair at all, you just point them at the tv. If yours has voice or works without pointing, open the battery cover and hold the little pairing button for about 5 seconds until the light on the front starts flashing, then leave it near the Roku for a bit. If it still won't take, pull the batteries, unplug the Roku for a few seconds, plug back in and try the button again once the home screen loads.