You might need only a tent & some sleeping bags. You can buy fairly cheap sleeping bags if you know you won’t be camping in cold temperatures. If it will be chilly at night, you can wear warm clothes including fleece jackets inside the sleeping bag.
The rest you probably have already. You can sometimes borrow a tent to see if you like camping. Another resource is campmor.com.
Click title for link.
UPDATE: Just got Aldi’s flyer today in the mail. (These special prices start Thurs., May 28th.) They have a 3-person dome tent for $25. I don’t know how good it is, but a dome tent is pretty easy to put up, in my experience. If you don’t like that one, you should be able to find a decent tent for about $100.
Aldi’s also has plain sleeping bags good to 40 degrees for $13. Some people buy sleeping bags for their kids with their favorite characters on them & use them opened up as comforters on their beds. They come in handy for visiting Grandma and sleepovers too.