It's frustratingly difficult to even get through the first lesson in which you are supposed to focus on your breath and minimize the wandering of your mind.

There’s the problem: trying to control your thoughts. Thoughts will come and you shouldn’t beat yourself up when they do. Be patient, keep practicing, and you’ll get better at focusing.

Alternatively consider something like box breathing. I use the iBreathe app and find that works better for me than meditation.