Q.something is eating holes in my plant leaves
What can I do to help my plant?
Whenever I hear about holes in plant leaves, the first thing I think of is slugs or snails. Probably because that's what troubles my plants the most. This article will tell you more about getting rid of the little monsters: https://www.gardeningknowhow.com/plant-problems/pests/insects/slug-snail-eggs.htm
Of course, there are many other critters that can eat leaves - different caterpillars, and bugs. Here's an example https://www.gardeningknowhow.com/plant-problems/pests/insects/what-are-flea-beetles.htm
Then again, since you didn't say what kind of plants or where they're located, animals could be munching on your leaves: https://www.gardeningknowhow.com/plant-problems/pests/animals/camouflage-gardening.htm
It all boils down to you're figuring out what's actually making the holes, before you can know how to prevent.