How to train a puppy?

I just got an 11-week old Japanese Spitz today and I was wondering how to train him.
Should I start crate training?
How does crate training work.
We haven t bought a crate yet but I ve been trying to teach him how to sit and I tried before.
I got his attention and held the treat over his head and slowly moved it back so he would sit instead he got angry and started barking.
Is he not ready to learn tricks/obedience?
My mum says I should take him out to poop but he hates his collar and leash.
Do I let him poop inside the crate? Or is it only for peeing (pee pads)
Thanks in advance!
Any other helpful tips would be great too
Added (1). Our backyard is fenced but its also got a lot of trees, bushes nooks and crannies so my mums afraid ill lose him or not be able to catch him…
Usually when I ignore him he ends up getting angry and barking.
Im trying to teach him not to bite by yelping like a dog so it seems like im in pain, it worked for a bit before but now he just growls and keeps going.

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