Jacob uses a classic shell with Windows 10 to make it look more like Windows 7. Leo says that the free Classic Shell is old and hasn't been updated for a while. So it's a security risk. Leo recommends StarDock. For further customization, they also make Windows Blinds and several others. You can get the entire library of utilities to customize your Windows OS for under $30.
What version of Linux should he try? Leo says that MX Linux/Debian is a good version for beginners. For more experienced users, try Manjaro. You can run some Windows apps on Linux as well, using Wine. But a better choice is to find a native open source app that's similar. Libre Office, for example, is the open-source alternative to MS Office.