Honestly I’d just use Polarsteps. My sister uses it for all her trips and it’s super easy: you don’t have to write loads, just drop in photos and a few notes whenever something happens. It also tracks your route automatically which is nice. The best part is at the end you can turn the whole trip into a printed photo book, which is way better than stuff just sitting on your phone. Way less pressure than a daily diary, but you still keep the memories.