Hello aspirant! I've got your question. It is pretty simple to find low competitive keywords through Moz.
Here are the following steps:
1. Go to Keyword explorer
2. Enter your competitor's site URL
3. Now set the keyword Difficulty according to your choice(e.g 15-20)
This is the most effective method that I have used to find low competition keywords with very high search volume for my glasvezelbehanger gezocht website.
I hope now your all confusion is gone.
Thanks!