It's good that you want to learn more about this lease with option to purchase arrangement!
Perhaps once you learn more, you will decide its not something you care to do.
I would want to ask you why you're considering this?
Do you think all the rent you pay will be used towards the purchase?
That usually isn't the case.
If you cannot qualify now for a mortgage, then you better make sure you will qualify when the lease period is up and it's time to buy the house.. or, you will forfeit any upfront money that will be on deposit.
Usually, there is upfront "option" money that is held and credited towards the purchase.
However, it is also usually non-refundable if you don't exercise your option (don't buy, or can't buy the house).
If you don't have any money to put upfront, you may then pay an amount over and above the normal rent - that amount will be applied towards the deposit.. Again, if you don't buy the home, that overage will be forfeited.
There are many potential problems with this kind of arrangement, and it usually favors the seller.
The sale price is agreed to now, rather than at the lease end..........if the house doesn't appraise out, when the time comes, you may lose that upfront money, as you won't be able to get the loan.
There are also possible issues on the seller's side - what if the mortgage isn't paid and the house goes into foreclosure?
My advice is...rent for now and work on whatever it is you need to do first.........then buy when you're ready and able.