Id've just started doing wrist curls, i see it working, but know my forearms are sore i stopped doing them today and also yesterday. hopefully some rest can help.

Any advice is good. thanks!

stretch them out. Stick one arm straight out in front of you with your hand and fingers pointed up to the sky... take the other hand and pull your hand back towards the top of your arm. Hold it for a few seconds.

Then...
point your hand down to the ground and take the other hand and bend it back into the bottom of your forearm.