It's federated with Lemmy.World so all the same posts will appear. I'm partial to that on Desktop browser, and stick with https://p.lemmy.world for mobile.
I found that a large number of communities have been named after popular, and less popular, subreddits. So I found them easy to find. There was an old r/Redditalternatives post that has a decent range of communities to start out, which I've copied below. It is similar to the default subreddits.:
*Note:*The "World" hyperlink takes you to the Lemmy.World communitiy.
It's referring to phone operation. Drivers are mandated to use a hands-free system like a headset or car speaker.