Modifying Your Home Page
Here is a great Trailhead module on modifying lightning pages.
To modify your home page go to your home page. And then click on the gear icon at the top right hand side of the page.
Rather than selecting Setup click on Edit Page and you should end up seeing something like this:
On the left hand side of the screen you can see all the different types of things you can add to your home page. The main ones that you are likely to use are reports, report charts, and dashboards but there are many options and you can experiment and decide what is best for your organisation to use.
The system works on a drag and drop option. Take some component from the left hand side, drag it to where you would like it and then customise it using the column on the right hand side. When you are done click save in the top right hand side of the screen.