I am traveling to Yosemite this year to camp for a few days while in California. Is there anywhere in or near the park where you can rent camping equipment (tent, cooking supplies, sleeping, etc.)?

Depending on where you are coming from this may be what you’re looking for.
For some items you may be better off buying new (cheap sleeping bag at Walmart for the price of the rental) or checking the 2nd hand stores for things like fold out chairs.