Keep a Journal/Notebook

Make sure you properly date and headline your notes so you can easily find them the next time you work on the project. Personally, I've had to work on a lot of quarterly projects, so it's definitely easy to forget some of the steps after three months. I referenced my notes multiple times during my first year to make sure I was following the right steps without having to ask anyone. You may not think this is too important, but at the end of the day, those you work with will trust you more if they can count on you to remember things (or at least reference notes you take) instead of asking them the same question over and over.
Ask Questions
Asking questions during your first year is vital to your success later on. You want to become the person other people reach out to when they have questions. It helps show you are on top of things, and it will definitely shine through for others to see. Keep in mind, you don't become an expert in any field without asking the right questions!
Ask for Feedback
It's also important to connect with your manager occasionally and ask for feedback on your work. Ask her/him for any advice to take your work to the next level. Make sure you know what's expected of you; you don't want any surprises when it comes time for your performance review!
Clear your To-Do List
If you feel you aren't being challenged enough, especially if you're six months in, this will give you the chance to ask for additional work. Keep in mind the type of projects you would like to work on. If you can specifically say to your manager, "I have some extra time and I would really like more experience doing ______", you will probably get a better response than just asking for more work.
Work/Study/Life Balance
It's also important to create a study schedule and develop effective study habits during your first year. Otherwise, it could be a long road to get your ASA/FSA or ACAS/FCAS. Find out about the study program at your company. Do they reimburse registration fees and exam materials? What's the limit on exam materials (number of materials or value)? Find out what others at your company are using to study. Keep this in mind and try to find the most effective study material that will work for you. Your company wants you to succeed, so make sure to use all of their available resources!