Not certain where you are - go to Target, Kohl's or JCPennys (I suppose even WalMart). All 3 stores carry "fitness" Apparel that is perfect for riding. Shirts that are made of a material that is lightweight and will wick away moisture. Cost $12 - 15 bucks each.
I got nothing on the shorts as I would recommend a good pair but if you have to go cheapo try Performance Bike. If you choose just to wear regular shorts (not cycling shorts), make sure they are lightweight and not cotton. They should contain lycra, polyester or spanex at least 15%. You can get those shorts at the above stores.
__________________
______________________________________________________________
Private docent led mountain bike rides through Limestone Canyon. Go to
letsgooutside.org and register today! Also available: hikes, equestrian rides and family events as well as trail maintenance and science study.