If you want a life jacket, there are a ton of options. Cheap ones function as well as expensive ones regarding actual floating… There is no safety risk in choosing an inexpensive option. However, if you aren’t strapped for cash, spending a little extra on one can go a long way in comfort. I’d choose one with less flotation at the shoulders because they rub your neck. If you have a sporting goods store near you, try some different shapes on to see what fits well.
Gender-neutral jackets fit men better. Women’s jackets build more flotation under the chest, so you don’t feel as scrunched if you are biologically female or have had gender-affirming top surgery. Both will be functional for safety and casual swimming.
I like the zip-ups for casual use; they’re easy on and off. The clips are generally annoying to clip on and off if you are in and out of the water, but if you plan to put it on and keep it on, they’re perfectly fine. Both will probably need an initial adjustment to the straps since they’re designed for multiple body shapes, so expect the first time to have to fiddle. Don’t worry about getting anything labeled “rescue vest”; those are made for rescue workers and raft/paddle/boat guides.
There are also inflatable options that would work for emergency use. They hang over your shoulders, are lightweight, and feel like a piece of fabric. Then, if you need it, pull a string, they inflate, and you pop up. A lot of fishermen prefer these since they don’t need constant flotation; they just want to have emergency coverage. It’s like sticking a fire extinguisher under the counter in your kitchen—you almost never use it, but if you need it, you’re glad you have it.
If you are in a place that doesn’t have lifeguards, stay with people and never remove your flotation. If you are around lifeguards, it’s nice to let them know you don’t swim well, you plan to stay shallow or only float, so they know that if you appear to be struggling or go under, it’s real, and they can respond faster.
Hope you get to have a wonderful, safe water adventure.
Edit-typo.