Lol girl my family owns like 10 nail salons let me help you out! So the gel can be misinterpreted a lot by people in the nail business and people who are clients and also people who do their own nails at home.
Gel polish is something very quick and easy to do. It's just a polish that dries very well and has a different finish to it. You can apply this onto your real nails and it'll be fine.
Then there's the gel that the nail techs talk about, which is you get an acrylic tip to your actual nail. (So it's like half of your real nail and half fake) then they start you pile on the "gel" which is completely different from gel polish. This gel actually looks and comes in a gel consistency. Afterwards you can choose to put the gel polish on or just regular nail polish.
For you I would recommend getting just the gel polish because your nails are sensitive. There shouldn't be any breakage and tearing in your nails after removing the gel polish. However if you go with the acrylic tip and gel application it will break down your real nail bed.
Gel nails are also fake nails. They are supposed to be marginally better than acrylic nails. It would be best to go to a salon for this than to try them yourself for the first time and end up doing much more damage than necessary.
If you have weak nails, I would not suggest you go and stick on fake nails as they will just damage your nails further. There is a great nail straightener called * Dr Lewinns Renunail Nail Strengthener * It really does work wonders.
I would recommend you for gelish nails or shellac nails as they are hardy and while they protect your nail they let your nail breath. Its best of both worlds, gel and varnish in one. They last up to 2 weeks too.
As For applying them yourself. I would say a no if you haven't got experience. You also need all the tools for the application of them. I would recommend some research before you try to do it yourself. I have tried many times but I fail because either they start peeling as I did not do they correctly and touched a side or I had crème on my nails, applied too much, applied to little. If your nails are already weak, I suggest you seek professional advice.
It's shinier and more durable than regular nail polish. It dries under a UV light and requires acetone nail polish remover to take off. Here's a link to a video of someone applying gel polish: https://www.youtube.com/watch?v=8D7_cp93b98