Some pools are only 1.2 or 1.5m depth the whole length of them - so an adult would be able to get their foot down always. Try and see if there's one of those near you. Probably a school pool or a hotel pool is the best chance of it.
And look at lessons too.
Try and find quieter times during the school day if you can to go, or else in the evenings (often there is a late evening swim in many pools that do it by the hour, that can be quite quiet).
And try to get a session when the whole pool is not made into lanes - fine if there's a lane or two, but still an open space for those not wanting to do lane swimming. So if you can't find a "one depth throughout" pool, just swim part way in that non-lane section: walk along the length of the pool to find where it drops away too much for you, find some landmark at that point (there's usually something you can use, a sign, a lifeguard chair etc - put a float on the floor if you need to). Then start your gentle swim, at your pace, to that point and back. Or go across the pool if there's no lanes marked - at a point that suits you.
You will find that even if you can't find lessons, that just getting used to the water and practicing your swimming, whatever it's like, will make it easier. Do it slowly, that's how to get the most out of it - flying along is fine for super-athletes, but to lose weight, you want to learn to do continuous lengths (long term goal here), and that needs the ability to do slow, controlled swimming.