Ratio of fish for a 20 gallon long

Hello! I’m working on my first planted tank and trying to plan everything in advance. I have already decided on what species I would like to keep, but am confused on the correct number of each. The species are

• Neon tetras
• Harlequin rasboras
• kuhli loaches
• 1 female betta
• possibly ghost shrimp

I believe these species have a low bio load and can be kept together, but please correct me on anything I have wrong