What is purpose of the dashboard?
Because you are a UX Newbie, I definitely recommend reading Information Dashboard Design by Stephen Few (Second Edition). This is will show you what makes a good dashboard (and what makes a poor dashboard). Sadly there too many poor dashboards out there caused by lack of knowledge.
For example, Pie charts are rarely useful because they are notoriously difficult to compare things, especially if the sectors in the pie are similar sizes. However bar graphs are excellent for comparing things. Every time I see a pie chart, I immediately replace it with a Bar graph, which instantly makes it better to compare things.
So firstly, you need to understand the intended purpose of the dashboard.
- Is it to compare similar things?
- Is it to show progress against a target?
- Is it to identify when things are going well?
- Is it to alert you when things are not going well (so that you can now do something about it)?
Once you know the purpose and goals, then you need to look at what data is available. You might need to make additional data, which means you might need to count things or combining multiple pieces of data, or even collating historical data. Getting the data you need can often be challenging.
Once you know the purpose and goals and you have the data you need, only then do you start thinking about the data visualisations that best support what the user needs.
Stephen Few has a website , where you can see his analysis (and his solutions) to common dashboards problems: http://www.perceptualedge.com/examples.php