Second the above.

Start slow, unbearably, frustratingly, skin-crawling-on-the-back-of-your-neck-it’s-so-slow slow and work up from there. Trying to play too fast is the number one issue for new, and especially young, musicians.

Pick two chords, set a metronome (plenty of phone apps) to 45bpm and swap between those chords on every second beat (stops things getting too frustrating and gives you more changes). When you can do that flawlessly for 15-20 changes change one of the chords. When you’ve got a couple of chord pairs under your belt increase the speed to 60bpm, then 80 -> 100 -> 120bpm.

If the song you’re learning has a cyclical chord progression, as many do, focus on those chords and once you have the pairs sorted move on to playing the full chord progression.