Getting your first place, you have more priorities than preps. But you also likely won't have a huge budget. Here's where I can help.
You'll NEED:
Furniture (at least a bed, and a decent chair, something to eat on (even if just a TV tray), as well as some place to put clean clothes) - Craig's List and local Facebook Yard Sale sites (for your city) are GREAT for this. Do NOT go to thrift shops and Goodwill etc. for this....as for some reason, they only overprice furniture. I would also recommend a couch/futon for friends to sit on, and a coffee table. You could also feel out your parents, see if there is any furniture they want to get rid of and get a new one, so you can take the old.
TV - If your parents will let you take one you already use, great, otherwise, pretty big expense, but check places like Craig's List for best prices most of the time. Can usually get a working HDTV for about 50-100, whereas a new one will typically run about 170 and up (at least here)
Kitchen Utensils (at least a few place settings, and some basics like slotted spoon, serving spoon, chef knife, ladle, etc.) - These are great to get at a dollar store
Glasses/Plates, etc. - These are great to get at a dollar store (for just a few place settings). WalMart and Target will have good deals on sets of these too.
Pots/Pans (at least a basic saucepan, frying pan, and baking sheet...don't go cheap here, get something that will hold up) - Don't skimp here, decent prices at discount stores like WalMart, Target, etc. even better at outlet type stores.
Toiletries - Something you likely never had to buy while at home (paper towels, toilet paper, shaving cream, shampoo, body wash, OTC meds, deodorant, all that stuff). - Great to get at dollar store too
Linens - Another thing you likely never had to buy before (sheets, towels, pillow cases, etc.) - Again, discount stores are good for it. Higher thread count typically means more comfort, but the price starts going higher and higher. Jersey fabric is a good, cheaper substitute too.
Cleaning Supplies - Again, something you likely never had to get. (get an all-purpose cleaner, like 409, a few chamois cloths, a floor cleaner, some dish soap, sponges, broom, dust pan, push mop, etc.) - Dollar store for most all of it.
As you can see, there is a LOT of expense other than just your rent and deposit to consider. Keep in mind you'll also likely have to put down a deposit for your Electric, and you may have a Water bill as well, or other kind of Maintenance Fee in an apartment. Not to mention if you want Wi-Fi, or Cable.
Not meant to discourage, just don't want to see you get hit with the surprise expenses.....