I’d try to change the
products =  line to be more “generic”:
products: any = ;
This should fix your problem.
The overall issues your are facing are due to inconsistent types, so far mainly due to the types you are using not lining up or not being defined. Its specifically TypeScript getting confused, and not Angular.
I recommend brushing up on TypeScript with the docs:
Angular uses TS, and requires a solid knowledge of how to deal with these errors and problems. Its possible your seeing more errors than the tutorial due to different settings/environments, which is one reason why I’m not a big fan of tutorials. Regardless, its good to know how to work around the problems you do face so you can continue along with the tutorial. The fact your running into issues might seem like an inconvenience, but your bound to run into them eventually anyways!
Good luck, keep building, keep learning