[Low competitive or high competitive gigs which are better now a days?]

Of course low competitive

[Completed 1000+ Order]

Congratulations brother for your achievement. 

[improve my gig.]

Optimize your gig properly and make it SEO-friendly perfectly. When your gig will be in the first page then it will be getting enough amount of impression everyday. More than 30 impressions is good for a gig.

Regards

[What is the average impressions of a normal fiverr gig]

Everyday average 30 impression means your gig is in well position and you can get 3-5 clicks or more everyday.

[improve my gig]

There is nothing other than waiting. Try to get order from previous buyer.