Software Engineering Intern

Heard this phrase many times, but would appreciate some elaboration/insights. Let's say I don't have ANY frontend experience in the past, but somehow get hired at a FAANG as a frontend dev. We know onboarding is already tough - meeting new people, understanding new codebase, etc. In the first few weeks especially, how do you manage so many things? You have to go through the onboarding challenges, and on top of that also ramp up on frontend. Isn't that too much to take on?