I have an inground pool, 22′ by 42 feet. I had a new person open it this year, and I think he forgot a step. I have a side drain in the deep end that is covered. Should that plug be removed when opening the pool? The suction does not seem to be as good this year. Please help! Thanks!!

Yes, all the plugs should be removed. I am sure this is contributing to your suction problem.