Great safety advice-
but why people think you have to go buy new sails for a rebuild project like this is beyond me.
If your sails are not serviceable you can possibly have them repaired by a good sailmaker at a fraction of the cost of new.
If that is out- measure the length of your mast and look around sites like this or ebay for used sails from other cats. Hobie stuff is always around. For learning to sail and just having fun, you do not need new sails. Same for rudders. Plenty of people here to help guide you with bringing the boat back to life.