I would recommend going through this list, that includes everything you will need for your kid to start playing soccer.
https://soccersoda.com/kids-soccer/

And especially, I would take care of shin guards to prevent injuries https://soccersoda.com/best-soccer-shin-guards/

Yes, the teacher makes all the difference. I also feel that they allow too many kids per class though. These are exceptionally big groups but then you don't get enough staff to kids ratio. As much as we love hanging out with friends last weekend's class, honestly put me off. I'd rather register for a class individually and be in a smaller setting.