Is it fine to add in Stop Leak before an oil change for a 2004 Ford Escape?

My father had the Ford Escape and wrecked it, destroying the bumper and pushing part of the hood back. The used-car body shop was able to fix it and put it back on the market. However, I discovered that there were leaks. I haven't really worked on cars before but I'm trying to learn now and I have the things I need for an oil change. When I talked to the clerk about doing the oil change, I also mentioned the leaks, and she advised that I try to stop the leaks first. A friend came along with me and helped me pick out a "Stop Leak", which I know would only be a temporary fix. I had thought about putting it in before I do the oil change this weekend. Is that fine, or should I do it right after the oil change? I know I need to take it to a shop and I plan to, but I need to save up for that. Also, what's a good store to get new carpet? I don't mean the floor mats, either, I mean the actual carpets that goes to the bottom and top of the vehicle. I want to change it to black carpet. I'm working on making it look better for Uber (since I will be driving for them soon.)

The cork gaskets Ford uses only last a few years before they start leaking. Top-leak won't help at all. Replace the leaking gaskets. Replace the leaking seals too.

The first thing for you to learn is to quit listening to parts store sales people! Stop leak products cause more trouble and damage then any other thing you put in a motor! You'll plug up small oil galleys and plug up the hydraulic lifters. You'll end up needing a motor overhaul instead of just a few gaskets.
But extra oil and keep an eye on the oil level. Watch a youtube video for replacing the valve cover gaskets etc.