Need some cheap casual wear this summer.

What type of weather? I had a guy friend who always looked neat in solid color t-shirts from KMart and cargo shorts.

I suggest going to Old Navy, you can get comfy shorts and tees that don’t look bad yet are inexpensive.

Nothing says I’m just relaxin’ like a Sarong and when ya go this route, you don’t need a whole variety of clothes. Wear it as a skirt, shorts or long pants, add a T for casual or a tux top for formal occasions.

shoes and underwear optional

If you have a membership to Costco, they have a lot of clothing for cheap. Like @janbb, suggested, I just bought some capri cargo pants at Costco for the summer. They are really light weight and short enough so I don’t feel like I’m wearing summer pants and long enough where I don’t feel every bug nipping at my legs. I like to be out doors a lot in the summer.
If you are a guy, you may enjoy mens bermuda shorts. I know it is my husband and sons favorite for the summer along with loose t-shirts. To dress it up. Wear a bright colored t-shirt with a short sleeve button down shirt and leave it open.
I do not know if your are looking for womens or mens clothing.

I don’t understand this: “Gonna be studying for a whole week, so i’m gonna be needing a whole variety of clothing.”

Why do you need a variety of clothing for one week of studying? And why does any of it need to be casual? Do you have to attend social events when class is done or something? If you’re just studying, informal clothes should be ok, and you shouldn’t need much variety. Maybe a few extra items if it will be hot and you don’t want to do laundry during that week.

Go to Goodwill and look around.