Warhammer 40k

Hi everybody :)

I'm not entirely new to wargaming, but I've never played WH40k before. So I have many questions about the game and some tooling around it. I'll start with universal questions in case answers may help some new players too and then I have a couple of questions about the faction I'd like to play. Thank you for reading it and I hope answering some questions :)

1. After a Combat Patrol "phase" what do I need to have to play a full Warhammer 40k game? Dices and measuring tape are obvious. But do I need to buy a codex? Do I need to buy a datasheet cards?
2. How to unlock information about datasheets and detachment rules in WH40k official app?
3. Are there any popular army builder apps or sites? Or we should stick to the official app?
4. When I need to specify units for Dedicated Transports? Should it be specified on an army roster list or it could be decided before the game? If it is former, how can I select it in the official app army builder?
5. The same question about attaching Characters to Bodyguard units?

Specific questions about Space Wolves:

6. New Codex has new Combat Patrol, but I can find this new Combat Patrol as a box to buy neither on the official warhammer.com site, nor on Amazon nor at my local stores. Do I need to buy units separately to play it as a Combat Patrol or it'll come out some time later (when?) or it was already sold out and I missed it completely?
7. Previous Combat Patrol has Battle Leader Thoryk in it. Can I pick him outside of Combat Patrol? If I can, than who is he: Lieutenant, Wolf Guard Battle Leader or someone else? I can find him neither in Legendary Proxies Table nor in Legends Field Manual.