Well, in my opinion, it depends on what drone you are flying, some are better equipped to withstand greater wind gusts than others. A Mavic Mini is not going to fight wind like a Mavic 2 Pro/Zoom could.
As a rule, I use UAV Forecast to check the wind profile and forecast at the location I plan to fly. its part of my pre-flight checklist. That app is available on Android and iOS, asd also on the web. Another good resource is Windy, again, a cross platform app and website. I use both. I always check 50meters and 120 meters and decide accordingly. Anything over 22MPH and I am not going there. I use a Spark currently.
As for your RTH question, the GPS data for RTH is recorded within the drone, its not dependent on your mobile device. When you take off, listen for the “The Home Point has beeen Recorded” voice prompts from the Go4 app, and then you are safe to fly your intended course. Again, best to take off and rise about 30 feet or 10m and then hover over your home point for 20 seconds… then go.
Hope this helps. There are no stupid questions really… and folks here like to help.
Welcome to the forum… as Goinup said, these are expensive drones, not toys, so attention to all this safety stuff protects you, your investment, and those around where you fly.