They might keep driving, but some infotainment features (or even other features that are tied to subscriptions) might stop working.
Depending on the implementation of these features that could mean the car constantly shows error messages, or the infotainment freezes, or in the worst case the car won’t even start or charge.
Some of these concerns are true for newer cars of traditional manufacturers: what happens when their online services become unavailable?
It really depends. You need to train yourself to focus on the important stuff and let the rest become second nature.
Driving a manual car usually doesn’t take conscious effort to do, you just… drive. But that takes practice. Lots of it.
And some people just never get there. Or they are afraid to drive, which tends to provoke dangerous situations. Or they can drive okay but don’t pay enough attention to the road.
But usually driving with an instructor is stressful, once you get your license everything will be more relaxed and easier.