See the search results for your query - sunscreen.
incidecoder.com
^ Sunscreens and their ingredients. Explains what they mean, ranks some stuff. The newer generation of filters provide greater photostability (Tinosorb S and M, Uvinul T and A) So that's what I look for.
Approx how much you should apply and what most people actually apply.
Face and Neck
Arms
Legs
Front and Back of Body ea.
Don't forget to apply to tops of ears, between toes etc. Areas most people overlook and where skin cancer is often found as a result. Also, they recommend you apply even more to your nose as the sun hits it directly and sweat, inadvertently rubbing it throughout the day etc removes some protection and it's a difficult area to treat - can leave the person disfigured.
Personally, I prefer UPF clothing.
https://www.solbari.co.uk/ It works out cheaper quite quickly and offers superior protection. Oh, and not as stylish but wraparound sunglasses are better, UV rays bounce off and damage skin behind traditionally-shaped glasses.