How do I get merits what are the criteria I need in other to increase or gets merits on this forum
If you want to get merits on this forum then you should focus on creating good and valuable posts. That's the only criteria to earn merits on this forum, there're many merit sources who're more than willing to help new members to earn merits but your focus should not be to earn merits but to make good and valuable posts and you'll see merits coming to your profile time after time.
I'll add a little, don't focus on how you want to get an award, especially merits. More on giving whatever is best for you and make your post worthy of getting it. I'm sure our friends here won't just miss your post if it's good and meaningful to them. If your post is useful but still hasn't received merits, at least you've given your best and can be useful for others.