blockchain network fee

I'm a beginner in crypto. I just want to regularly buy gift cards (average price of each: $50) with my ethereum and I want to pay the lowest blockchain network fee. Right now, my ethereum is on coinbase. I was looking to compare fees for ethereum transfer. I saw on reddit this: https://fees.growthepie.com/
But it doesn't show coinbase on this list. I don't know the meaning of Median fee, Transfer ETH and TPS. But I understand that Unichain is the best. What is the approximate median fee of coinbase? Should I rank each Chain according to Median fee or Transfer ETH? Should I switch from coinbase to Unichain?
Sorry for asking so many questions.