The settings are all located on the General tab:
The first one is to set your home page. By default, it's set based on your user role but you can change it to a specific area of CRM. When you're first starting out, you may not know what to choose so you can leave this one for later if you'd like. Once you have a better idea of where you'll be spending most of your time, you can come back to make the change.
Next, set the number of records per page to 250. This my not be everyone's preference but I find it very helpful so that I'm not spending time flipping through pages of 50 records at a time. That could take a while if you have a lot of records!
Finally, change the default mode for Advanced Find to Detailed.
This will change your Advanced Find from looking like this:
to this. In the original view, it's not obvious which fields can be edited. It also doesn't give you the option to add more lines. In the detailed view, you can add/remove lines and change the existing queries as needed.