Vinegar helps counteract the toxin for most jellies. I also have friends that swear by bentonite clay, which helps absorb the toxin and soothe the rash, but I haven't personally tried it. It's definitely a good idea to look up what critters are in your waters, both for how to keep yourself safe and for you to avoid disrupting their habitats.
And congrats! I also taught myself how to swim. I recommend joining an open water swimming group if any are around your area, you can learn so much just by watching how they swim.
I've been using inoreader's free tier for years, happy to see it mentioned in the article. On top of deshitifying your news feed, accessing by RSS is often enough to bypass the free article limits or subscriptions on a lot of the news and journalism sites.