If you haven't yet had to support yourself, you may indeed find some surprises waiting when you go out on your own. For example:
You have to have a place to live. Depending on where you live, apartment rent can run from $600 per month to $1000 per month, and in some cities, the rent can go even higher. If you want water, gas, and electricity with that, you may be paying from $100 to $300 per month for them, again depending on where you live.
You have to eat. Depending on whether you cook or depend on restaurants for food, you may need to set aside from $35 per week ($160 per month) to $300 per month (or more) for food for a no-pet household. Add a pet and you add to the total.
You have to have transportation. In cities, you may be able to rely on public transportation such as buses and trains. In small towns, you may find yourself owning a car--and insuring it. If you drive 10,000 miles a year, which is average, the car will cost you $5000 per year or $400 per month to own--once you have paid the down payment and monthly payments, which will be determined by whether you buy new or used and what make and model you select.
You have to have clothes, particularly if your job requires a certain "look" or a uniform. You also have to be able to clean them, so figure on $1 for each wash load at the laundromat.
You have to have incidentals, such as shampoo, cleaning supplies, and paper towels.
You don't have to go to the movies, go for a beer after work with the gang, or give gifts to your loved ones on special occasions, but you might want to do that.
Other than a mattress on the floor, you don't have to have furniture. However, it is nice to be able to sit in a chair.
You don't have to have a telephone, but you might feel safer if you do. Figure between $80-$150 per month, depending on your rate of calling.
You don't have to have a television or computer with Internet connection, and if you do--and get them from the same provider--you may get them for between $75-$150 per month.
You may find that you are happy with your job, or you may find that to advance and earn a larger income, you need to have at least some college training, either a certificate, a diploma, or a degree or at least certification of competency in a field. If you earn too much money to qualify for financial aid, you'll need to pay for your further education yourself, perhaps one course at a time (for between $200 and $500, including books and fees).
It would be a good idea to find out what "things" cost where you live and what it would cost you to maintain the lifestyle you'd like to enjoy, and then reflect on whether or not you will be enough ahead in 1 or 2 to 5 years to make it worth while to stay out of college now and start paying for your lifestyle, or whether you'd have been better off to postpone going out on your own for 1 or 2 to 5 years and then starting at zero, but with a college degree. (One year to get vocational training in cosmetology, practical nursing, machinist, mechanics, and so on; two years to get an AA or AAS degree in nursing, a technical field, or advanced skill area; five years to get a BS or AB degree).