There is a lot to learn and it is a science, but the more you read and watch (some youtube posts are really good), the more
it will make sense. The kits instructions can lead you astray, to start with the yeast probably aren't what they say they are.
They will flog their sanitizer, just get starsan ( it's a 2 acid mix). Lots of great ideas on this forum and we've all been there and
stuffed things up so don't give up.