I did a lot of climbing a few years back. Climbed indoors 3-4xweek during the winter for training for summer outdoor climbs. It was so fun and always challenging both physically and mentally. Make sure you stretch before and after and yes, your forearms will be sore for a little while. There are so many levels of climbing. At first you will be what is called " top roping" which is fun and a "safe" way to climb. Once you get the skill set and experience you may eventually be able to lead climb which puts you more at risk for falls, but in the gym it is not too bad/dangerous to take a lead fall. Just find a partner you can trust that will be paying attention.

And of course have FUN!!!