Learning Looker and ramping on to client work does happen at a fast pace. It can feel slightly overwhelming at first. You have to be comfortable with feeling slightly uncomfortable during the ramping period (3-6 months). I have learned that this is how I grow the fastest, so it ended up being a good thing for me.
You have to be comfortable with a bit of ambiguity and be someone who can take an ambiguous situation and have the initiative to turn it into scope that adds client value. This may be true of all client work, since there is a common saying that "clients don't know what they want". It is definitely true here that you often won't be handed perfectly scoped tasks to do. You will be gathering the requirements, turning them into the tasks, and then doing them. The good thing is that you are fully supported until you are Looker certified and feeling more comfortable in managing clients on your own. But if you think you are someone who will never be comfortable with ambiguity, then this might not be a good fit.