Subdivide tasks & find a buddy
When you first start as a junior, it's easy to be overwhelmed by all of the new information that's being thrown at you. It's also easy to feel like you're stupid because you don't understand "basic" items on the to do list.
The #1 trap a junior can fall into is feeling so overwhelmed by a task that they take 5 days to do a 30 minute task.
They don't know where to start, they try and figure it out themselves, they get stuck, they take a break, they get stuck again, they feel overwhelmed, they put off working on it, they don't communicate exactly what they're struggling with when asked, instead saying something like "I'm making progress on x" instead of "While working on x, I got stuck at step y, does anyone know how to fix that?"
This turns into a vicious cycle of falling further and further behind until you're so worried about asking about the first steps in the process because it will show you haven't done anything in 5 days.
Before doing any real work, when you are getting started on a task, try making a list of what you think needs to be accomplished to finish the task. Then, find someone (preferably closer to you in skill level, not some high level senior*) and ask them if they agree with your list of what needs to happen. Some of the time they'll tell you yes, it looks good. Other times, they'll tell you that half of the items on the list don't need to be done.
Then, when you get started on the task itself, schedule frequent check ins with them to make sure you're on track. When I say frequent, it could mean you pair with them and they step you through every step. It could mean sending them a message every hour. It could mean twice daily check-ins. It depends on the amount of structure/help you need. But by scheduling time to work, it forces you to continue making progress and prevents falling into that "doom loop".
*By having a buddy closer to your level, you can feel more at home asking them "stupid questions" which you might not want to ask your boss.