Make a plan
As a manager, planning is an essential part of your job. It is a basic expectation of a manager to be organized and prepared for most reasonable situations in the near-term. Moreover, this is the planning for yourself and your team or project.
Considering this is your first week, it's reasonable to have only a high-level plan, rather than a detailed, fully formed strategy to take over the world. The important thing is that you have started the process of planning ahead.
When it comes to planning for your team or project, you should first work out where you are now. For a team and its people development, try a technique such as a simple SWOT (Strengths, Weaknesses, Opportunities, and Threats) analysis or maturity assessment to determine the starting point for each team member and the team as a whole.
One of the first things I always do when building a team from scratch or joining to manage an existing team is to create a "team deck". This is essentially an introductory guidebook to who your team is, what it does, and how it operates. It's also a mini sales brochure that can be used to promote your team to stakeholders and prospective new customers. Your team deck should contain your team's mission, as well as how it's looking to improve.
Once you have a reasonable idea of where your team or project is currently in terms of maturity or progress, you should map out the immediate next steps required to improve or move forward. This will naturally be a list of actions, such as finding training courses or running another design workshop.
Most importantly, keep your plan simple. Write it in a simple way that is easy for you to update and improve on regularly, as well as easily understood by others. As a general rule of thumb, a good first-week plan should fit on a single A4 page, which you can share with your team, your manager, and your stakeholders. Remember to invite them to feedback and openly accept this as an opportunity to improve it.
The underlying idea is to demonstrate your own progress with settling in and adding more value, in order to gain the confidence of your stakeholders.