You can actually change how many emails your inbox shows by going to Gmail’s Settings and then searching through the General tab for the Maximum page Show option.
When you download and install Gmail, the default setting is to show 50 email conversations in your inbox. This Google Guide will also give you more information about each setting and will also show you how to set up multiple Gmail inboxes. Go through each of these and pick which one suits you the best. You can choose between showing Default, Important emails first, Unread first, Starred first, and Priority Inbox. Clicking this arrow will open up a menu of all the different types of Inbox configuration Google offers. When in Gmail you can hover your mouse cursor over Inbox and you’ll see an arrow appear that is pointing downwards.
You can customize your inbox with a simple click of a button. Google gives out some good information on customizing Gmail and the first step it says all users should use is a simple one.