Your situation is not dire, but you are about to make it worse if you do find a vehicle loan. Forget about a vehicle loan for now. The only loan you, or you and a cosigner, will find will be one from a "Buy here, pay here" dealer with an exorbitant interest rate. Instead of buying a good vehicle with a bad interest rate, buy a cheap vehicle you promise yourself will be a short-term purchase while you get your finances in order.
You can tackle the three debts you listed using one of two strategies.
The first strategy is to take a shotgun blast at all debts and pay a small amount to each every month. The advantage to the shotgun approach is it is unlikely any of your creditors will bother filing a lawsuit against you because you are paying down your debt, albeit slowly. The disadvantage is you cannot bring any leverage to bear and focus on any one debt.
The second strategy is called by several names, including domino or snowball. In this strategy, you take whatever money you have for retiring your debt and focus it on one debt at a time. Some people using the domino strategy like to pay-off debts from smallest to largest because it gives the most immediate gratification. Others pay off the debt with the highest interest and monthly fees first to minimize cost.
Each person is different, and everyone has a different number of debts and balances. Pick a strategy that works best for you in your situation, create a plan, and work the plan.
You mentioned that building your credit score is a priority. Focus your efforts on the accounts that are reported to the three credit reporting agencies. If all of your debts appear on your credit reports, then consider a domino strategy where you tackle the phone bill, then the electric bill, and then credit card.
If the credit card has been written off and was sold to a collection agent, you may be in luck. Collection agents can work on behalf of original creditors. Generally speaking collection agents buy collection accounts from the original creditor for pennies on the dollar. The collection agent still has the right to collect the original balance.
If the owner of the collection account is a collection agent, save your debt-retirement funds for several months in a separate account. Then approach the collection agent to begin negotiating a settlement on the debt. You mentioned the credit card debt is $800. After you save $200 or $300, contact the collection agent and start negotiating. Then work on building your credit score.
I hope this information helps you Find. Learn & Save.