@Christine Krevalin it sounds like you're moving in the right direction! My first piece of advice would be to cut out the law office, save your money and reach out to the creditors yourself. Been there, done that. Back in the day as a teenager, my husband had some health issues and ended up with bills in collections since he didn't have health insurance. We called each agency and negotiated much lower payments. If you can commit to paying a lump sum instead of setting up payments, you might be able to get a bigger reduction.
If you choose to go this route, you should ask for a pay to delete. Just because you pay off a bill in collections doesn't mean it won't remain on your credit, but if you ask for this letter, there's a chance you can get it wiped off. Also keep in mind that you're closing an account and while it's great to pay off those debts, that will have an effect on your credit score as well. This whole process will take some time, do not be in a rush.
There are different types of loans depending on the situation. DSCR loans, for example, look at the cash flow of the property and don't require income documentation from the borrower like you'll find with a traditional loan. However, most lenders will want to see a score of 640 for this loan, and even then, your rate and terms won't be great. 700-720+ is ideal. These days, you'll likely need at least 20% down and they have more fees than a traditional loan.
You can look at conventional financing, but your income, DTI, credit, job history, etc. will all be considered. For a single family, you'd need 15% down. MFHs 25%. You can't get an FHA loan on an investment property unless you plan to move into a MFH and live in one of the units, then you can get away with FHA and 3.5% down. Don't forget to account for title fees, inspections, appraisal and other closing costs on top of down payment. I recommend that people have at LEAST another 5% for closing costs. It could be higher, could be lower, but that's a good starting point.
Credit cards aren't bad IF you use them properly. They are a great way to help build your credit back up. I usually tell people just to use it for a necessity, like gas, and then pay it down or off. To avoid paying interest, you could split it into 2 payments and still show a balance on your credit reports. For example - if you have a balance of $50, you can pay $25 before your statement end date. Then when you get your bill for the remaining $25, pay it off. This way, a $25 balance will be reported instead of $0, and it shows that you are able to manage your debt instead of always holding a $0 balance and you aren't charged interest.
Your income is good - work on a personal emergency fund and an REI fund. Don't wrap up all of your money in an investment and put yourself and your kids in a tricky situation.
Save up, get your accounts settled and work on repairing your credit. You don't want to buy a property and kick yourself because your tenant didn't pay rent, and now you can't make the mortgage payment. Or worse, your own mortgage payment because all of your money is wrapped up in your investment. Things can and will go wrong, you just don't know when, so preparation is vital. I'm happy to discuss anything I've mentioned in more detail if you need me to, otherwise good luck on your journey!