Best soil for sand capped substrate?

Hello! I'm new to the hobby and was planning to get some fancy guppies with cherry shrimp for my ten-gallon tank! I heard that sand-capped substrate is best for plants. The problem is, idk whats a good kind of soil to get! If anyone could give me some good brand names.. Last time i searched online, it gave me soil that was NOT good for it.. Please help!! Thank you!!