You probably cannot pass a home study right now and an expectant parent is unlikely to choose you at this stage in your life.
In most modern adoptions the expectant parent(s) choose the adoption parents and most are unlikely to pick someone who isn't independent (lives with parents), unmarried and has a low income because for many that's the same situation they are in and don't feel they can adequately parent the child. They want a better life for their baby that they can't provide to them where they are in life.
For every baby expected to be placed for adoption, there is 40 applicants for that baby. The competition is quite stiff. I'll use my personal situation as an example of the competition .. My husband and I have been married for 16 years, we own a home (several actually), we are both very well educated, my husband is a Physician and I'm an IT Engineer. Both of us have 6 figure incomes, but we can also live quite well off just his income and I could be a stay at home parent if I wanted to. We also have adopted before. We can give a child a stable home life and quite honestly at the risk of sounding uppity or bragging we can offer a child a privileged life and upbringing. Our family is complete so we're not looking to adopt any more, I'm just using us as an example. There's a lot of couples like us waiting and even single people who are very well established that can offer a child the same thing we can.
Adopting a newborn in the US through a private adoption costs a good $25,000 give or take. Plus you're required to pay for the expectant parents legal fees (their attorney) and you may be required to pay some of the expectant mothers pregnancy related expenses things like food, rent, cell phone bills, doctor copays and things like that. If the mother changes her mind and decides to parent after she gives birth, you're not reimbursed any of those expenses you've paid for her.
A home study is about $1000-3000 and that consists of criminal background check, fingerprints, financial disclosures, 3-5 references, interviews with you, a physical from a physician, parenting classes, and a physical inspection of the home. Since other adults live in your home, they have to be part of the home study too. They would be subjected to the background check & fingerprinting and interviews.
I actually did adopt as a single parent and at the time I was living with my mom. I moved back in with her after my dad died to help her financially and with some medical issues she was having. I was who was financing the household and the few years I was there I paid her house off. I didn't have any problems passing the home study, but I was also older than you and more experienced and established in life.
Another way is a direct placement adoption, generally where the expectant parents know you. That still requires a home study and legal fees. This would be a few thousand dollars (usually in legal fees).
The last way is foster care. Foster care adoptions are usually free or low cost. There's still a home study, but a home study done via foster care is free. It's unlikely though to get an infant or newborn, most kids free and clear for adoption in foster care are over 3 years old but it can happen.
If adoption is in your heart. it still will be when you're older and more established in life. I knew when I was young that I wanted to adopt and when I was in the right position in life ... I did.