From what I can tell your problem is simply that you have too little credit. You have too few credit cards and loans, with too small of credit limits, and your open accounts are not old enough.
Also you have a few hard inquiries, but those will go away soon enough. Nothing you can do about that but wait.
You need to do the following:
- Don't close credit card accounts. Especially not your oldest account. You don't have to use them (just use them enough to keep them alive), but don't close them. For at least the next decade, do not close any accounts.
- You will want to open some more accounts, though you will likely need to wait until your score goes up when those hard pulls inquiries off. Store credit cards (like a J C Penny card) are one option if you can't get a good credit card. Also consider opening a line of credit with your savings account bank. Again, don't use it, just have it. Wait a while until at least one hard pull falls off and then open a credit card somewhere you know you will get approved (don't want another hard pull without getting the benefit of a new credit card).
- As your credit gets better, ask for an increase in your credit limit for each credit card you have. Do this once a year, or once every 6 months if your credit gets good.
- Make payments on time on all your accounts, always. Obviously.
- Keep balances low on any credit cards you get. Maybe buy something really big with them but then pay it all off as soon as you can.
That's really it. Having good credit is not rocket science. You just need lots of credit cards and a loan or two, all with 100% on-time payment and plenty of unutilized credit capacity. And you need it for some years. It sounds like you have been doing the opposite of what's needed (by closing accounts and maybe avoiding opening them).