starting sorority 20 gallon

So this is currently my 6.8 gallon long fin betta set up, i have 8 neocaridina shrimp with him, two mystery snails, and two nerite snails. I am researching the possibility of a sorority tank and just wanted to come on here and see if i was experienced enough to accomplish one. i test water weekly because i get very nervous lol. i use sand as substrate, all live plants ofc, seashell for calcium, live mosquito larvae and pellets for my betta, calcium tablets and algae tablets for the shrimp and snails. i dont have to do often water changes, but am willing to if needed for a sorority. I was thinking about 5 girls in a 20 gallon 24 by 17 inches. maybe some corydoras if possible, and heavily plant it. I was wondering if anyone could tell me how long to cycle to new aquarium before adding the bettas. I know I can use my established tank to jumpstart it but still don’t really know much about timeframe for cycling when using an established tank to start the new one off. Any advice would be great even on my current tank pictured above

So this is currently my 6.8 gallon long fin betta set up, i have 8 neocaridina shrimp with him, two mystery snails, and two nerite snails. I am researching the possibility of a sorority tank and just wanted to come on here and see if i was experienced enough to accomplish one. i test water weekly because i get very nervous lol. i use sand as substrate, all live plants ofc, seashell for calcium, live mosquito larvae and pellets for my betta, calcium tablets and algae tablets for the shrimp and snails. i dont have to do often water changes, but am willing to if needed for a sorority. I was thinking about 5 girls in a 20 gallon 24 by 17 inches. maybe some corydoras if possible, and heavily plant it. I was wondering if anyone could tell me how long to cycle to new aquarium before adding the bettas. I know I can use my established tank to jumpstart it but still don’t really know much about timeframe for cycling when using an established tank to start the new one off. Any advice would be great even on my current tank pictured above