First off, welcome to the wonderful world of Tableau! There are plenty of amazing resources out there for learning Tableau. I would definitely not be afraid to check out any and all things available!
Tableau has some great options in the Learning section of Tableau.com : Learning | Tableau Software
There is also the phenomenal Think Data Thursday program hosted by Patrick Van Der Hyde and myself on Thursdays throughout the year. Stay up to date on #TDTs by following the Community space.
Also check out all the amazing past Think Data Thursday in our playlist found here: Think Data Thursday & Talk Data - YouTube
There are some groups on Twitter that also do a great job of expanding knowledge with weekly challenges. Check out the hashtags #MakeOverMonday and #WorkoutWednesday.
For this particular question and for future posts, I would suggest attaching a packaged workbook, this allows the Community to get a clear understanding of what is being encountered. This can lead to quicker assistance on the issue as well.
Hope this helps!