Getting comfortable with timechart is key to getting comfortable with Splunk. It's the core of your first reports in the system.
Take a look at the below posts for a shortcut to going from basic to advanced with timechart:
- Basic Syntax
- Advanced Statistics
- Analyzing Trends (Comparing Summarized Hours, Days, or Etc.)
- Using Eval Within Timechart (or how to make your searches 20 times more performant)
- Timechart versus Stats
While you're at it, you may want to take a look at a couple other introductory posts about Splunk:
Finally, if you're really into Timechart, dive into some advanced Splunk: