IMHO the first thing you have to do is make a budget. I like to use a spreadsheet. Create a number of categories like: housing expenses, utilities, groceries, transportation, entertainment, etc. For a few months write down every penny you spend in each category; this is called your baseline. Once you have this create a budget of how much you plan to spend in each category. Every month compare what you plan to spend, how much you actually spend, and the difference.
When I was your age I discovered that ordering out for pizza every day for lunch at work will eating up 25% of my income! I started to eat cheaper meals or bring my own lunch. I had an old car that was breaking down every month and I figured out that for what I was spending keeping the clunker going I could afford a more dependable car.
The key to getting ahead is to live below your means.
Most communities have free financial advisors. Check your yellow pages. If you are bringing in a paycheck and lets say you take home $2000 a month and your expenses are $2500 a month than you can see you are $500 short. You then know you need to find a way to cut $500 from monthly costs. Also make sure your rent, utilities and food are taken care of...transportation is next making sure you either have all car expenses cover or bus pass. The rest you can look at as extras...it is the extras that get us. If you have a lot of credit debt go to your bank and see an advisor there. They can consolidate to make things easier for you. Sometimes the simple things like taking your lunches to work instead of purchasing them can save a ton of money. Always ask for help...a lot of advisors are free.