Chalk bag and Brush
Next up, it’s a great idea to bring a chalk bag full of chalk. Same as the shoes, no matter what kind of climbing you do (again apart from ice climbing) it’s gonna help a whole lot, unless you’re Janja Garnbret and can top a route in the world cup after losing your bag on the second hold. The chalk is used to dry your sweaty palms, giving you better grip on the holds. But beware, you can use too much of it, then it just makes you slip off the holds and it’s sort of counterproductive.
The third piece of equipment is a brush which sort of goes together with the chalk. Now again there is many kinds of brushes some being fancier and more expensive, but in essence it’s just meant to get some of the excess chalk off the holds and help with a better grip. It’s especially helpful with that old chalk mixed with rubber and grime that can be found adorning the holds in super busy gyms. If you are only planning on climbing indoors, you might not even need a brush since lots of gyms have them lying around for people to use. Or of course you can just bother other climbers to borrow theirs, but I guess that goes for any piece of equipment (apart from shoes maybe, because ew)