Good morning.
Unfortunately your post gives far too little detail for me to help much.
The Swimming Thread gives loads of basic information and I suppose you have studied this already. (Post 3 has relevant addresses etc.)
You don't say what level of swimming you are at and what you want to learn. Most of the Swimming Schools cope principally with children, but some teachers also have adult groups of improvers or 'would like to be able to swim crawl' breaststrokers. There are hardly likely to be many adult beginners groups in English, but at a rough guess, many swimming teachers will be able to muddle through with English if requested. Swimming has its own vocabulary anyway, so the language of the lessons is not of primary importance to the learner. A good teacher will show from the pool-side what he or she means and you will be able to see what 'the others' are doing and follow suit.
Hope you find what you are looking for.