When you use macOS Catalina's built-in screen recording you'll get audio only from the microphone. If you want to record the audio coming out of the system and apps, you'll need to install a third-party extension. One company provides an extension for free that you can use with their software or just with macOS QuickTime screen recording.
In Safari you should probably not have so many tabs open that you can’t find the one you want. But if you do end up with a lot of tabs and want to organize them, you can choose Window, Arrange Tabs By and sort them alphabetically. You can choose to use the domain name of the site, or the title of the page to sort.
When you use Command+Tab to switch apps, you can press tab while still holding down the Command key until you get to the app you want. While doing that, you may know that you can also press Q to quit the currently selected app. You can also press H to hide or unhide that app.