Hello, and welcome to The Passion.
Your doing great for a first time.
Heed the warnings for those mites. You don't want to waste your time and money on a plant that you can't even finish or worse, Finish and cant smoke.
Growing is a trial and error type of hobby. Especially brand new growers. You will make mistakes. Most of us will admit that we have made plenty. The ones who say they haven't are just lying.
Just learn from them and improve on your next cannaventure.
Yes you can find great resources on places like Marijuana Passion, but words on a page will not 100% reflect on your grow everytime. The reason behind that is all growers have differences in their room, tent, closet, basement, shed, backyard, or even a gorilla field somewhere. Temperature, Humidity, PPFD, lighting type, medium, and strains are almost never mirror images of one another.
Even if you and a friend use the same strain, lights, tent, medium, etc. The resulting grows will have differences. So just keep learning from whoever and whatever resources you can find.
As directed above, get some neem oil spray or Grower's Ally spider mite control spray. Shouldn't run you more than $20 a bottle on Amazon.