@Travis W Condon As mentioned above, keep your business separate! You do not want to mingle your transactions, which makes everything very messy. LTR is very easy to keep up with since it has minimal transactions, usually very repetitive. You shouldn't need QBO Plus for this, I would think QBO simple would be easiest and put your properties under customers. It may be a little difficult because you can't do line items by customers but if you aren't going any renovating or a lot of expenses, it should work fine. You can run both businesses in QBO under two different subscriptions and keep it on the lowest subscription.
Now all that is if you decided to use QBO. If you don't have a lot going on, you may want to use Stessa or Excel. Don't add another expense in there if you don't have to as long as you know you can keep up with each transaction. I've never used Stessa but if you do excel just use a new sheet for each business/property and there you go. Just make sure to keep up with all the other information needed for your properties not associated with your "normal" expenses and income. (land vs home value, depreciation, closing costs, etc.) Hope this helps :)