You're on the right page, simply scroll down to see Pitches. Also, check out the Custom Object Permission sessions to see if yours has it set up like mine.

The Pitch tab is probably hidden so you'll need to check your User's Permission. First click on Home tab (next to Setup tab on the top left corner). Then click on System Administrator, it'll direct you to Profiles setup page. Scroll down to Tab Settings and check if Pitches tab is Default On. If not, set it to Default On. If it's already on, scroll down to Custom Object Permissions to check if all Basic Access is checked. If not, edit to check all boxes. If they're all set and Pitches Tab is still not in the Available Tabs under Marketing App (in App Manager setup), the problem is not on User's Permission, then we'll need to find out other possible issues.

Attached link explains why custom tab is not visible. Feel free to check it out!

https://help.salesforce.com/articleView?id=000330223&type=1&mode=1

Well, in Steps 72-78 you would have created that Pitches tab so it should show up. But if you are doing the labs on your iPhone or have you have a narrow window in your browser, the Marketing App may not have room to show all the tabs, so there might be a "More" tab at the far right with a down-arrow. Then you click the down arrow to see the tabs that won't fit and Pitch should be there.

Give that a try and let me know. If you're still not seeing the Pitched tab and you don't see More either or you don't see Pitch when you click More, then reply with a screencap to show what you're seeing so we can help better ok? Thanks!