Rate and terms: no clue. Opportunity cost would be doing this instead of dumping it into equity index funds.
Since you say you want to learn, here's a good exercise: go talk to some local lenders and ask them about their options in your price range. Most likely, you will find that available financing for properties valued at $50K or less is limited, and rates and terms are not as attractive. For various reasons, many lenders have a minimum loan amount of $50-60K for mortgages, which generally means a $62,500 or $75,000 purchase price at the
de facto maximum of 80% loan-to-value (LTV). Lower amounts often force you to use other types of loans, like unsecured personal loans or business property loans, where rates can exceed 10% and payback periods may be shorter.
For this reason, once the value of a property falls below that general threshold, price becomes highly negotiable and cash buyers willing to rehab distressed properties can find great deals... but unless you grew up doing construction and can handle a large project on your own, or have a partner with those skills who will cut you a deal on costs, that's a challenging first buy for a new landlord, with high risk involved.
But like I said, contact your local institutions and see what that picture is like, because these things do vary with location. Understanding how banks evaluate credit risk on investment property loans is a real step toward understanding how investment property works, and knowing your options (in detail) is key to making good decisions. Take your time and learn as much as you can before making a commitment like this.