I would say most black teas would work, though maybe aim for a mid-tier rather than the cheapest (if you can afford it). I recently switched to an organic loose leaf black tea, that I really like. I don't find it crazy expensive since you're only using a few teaspoons of loose tea per batch. Positively Tea Company is the name, it's on Amazon and their website and they have sample packs if you want to try different styles of black tea to test.

As far as how to get started, I would recommend buying a SCOBY. I started my own from store bought raw unfiltered kombucha, but recently bought a new SCOBY directly. The difference was night and day. The bought SCOBY is way more active than the one I started myself. In hindsight, I wish I had just bought it from the beginning lol.

SCOBY:

https://www.amazon.com/Fermentaholics-Kombucha-Twelve-Starter-Culture/dp/B01N7S1CV5?ref_=ast_sto_dp

SCOBY + Kit:

https://www.amazon.com/gp/product/B07C86JGJG/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

Link to organic tea:

https://www.amazon.com/gp/product/B00GA91LJY/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

I could not find unflavored kombucha in my area. So i bought a starter off Amazon that had good reviews. It’s worked well… no ice pack or anything though. Not sure how it would fair in 100+ deg heat though.

This is the stuff i got:

Fermentaholics ORGANIC Kombucha... https://www.amazon.com/dp/B01N7S1CV5?ref=ppx_pop_mob_ap_share

Edit:

There are also active Facebook kombucha groups where you can post a request for a scoby… there may be someone near you.

While alot of people use it that way, it still doesn't make it correct. Reason being is that if you think you need a pellicle then someone can sell you this for 13$ or you could buy this GTs Original-- not watermelon-- for 3$. So its not that we're trying to be a dick about it when we try to correct people's widespread misunderstanding, if anything the people selling things you dont need for a 3x markup are the real dicks. But we're trying to help.