First let's take a look at some exercises you can use to practice your open chords with the metronome. I'll show you a bunch of different ways to work on this, but the idea is not for you to sit and do every exercise that I show. The idea is for you to understand how to come up with exercises that can help you improve something specific you might be having trouble with.
You can choose any of the open chords to play along with the metronome, but here we'll just go between a simple A chord and the slightly more challenging Csus2 chord.
We'll start at 80 beats per minute (BPM). You can start at a slower or faster tempo, but don't go too fast! The idea here is that we'll bump up the tempo by 2 beats per minute, slow it by 1 BPM, then faster again by 2 BPM, and so forth.