3 Models
Think of your model(s) at the physical location of raw data and metadata. In the more formal sense, there is an entire field of data engineering and science that has to do with database design and modeling. An excellent way to get your feet wet is understanding database normalization and take a look at some entity-relationship diagrams. You will quickly realize the limitations of your Frankenstein multi-tab Excel sheet.
3.2 Love the data you have
Data is everywhere but you only have access to some of it. Getting access is often time consuming. Once you have access to data you should consistently assess its strengths, weaknesses, opportunities, and threats (SWOT). In the name of deliverables, you have to have endpoints. Your productivity will be judged by the consistent quality and quantity of work.