Degoogling - can someone ELI5 how certain apps work on Graphene OS?

Hi,

I am (very, very early) in the process of degoogling. I am definitely not a high risk as far as needing to be completely locked down. It's more about trying to have a little more control over how my data is used.

I am looking at Graphene OS, but I am a little confused how certain apps (that rely on Google services) work. I have a Pixel 8 and will have it for the foreseeable future.

The apps I currently use that I would still need (or their equivalents) are:

• Clash Royale (Supercell)
• Notion (Notion Labs)
• Clickup (Mango Technologies)
• Business Calendar 2 (Appgenix)

1. If I installed these exact apps "sandboxed", what exactly does that mean from a user standpoint? Will I have to use a separate account, reboot my phone, etc, or is it a quick process to use the app?
2. Is there a list of apps that I could browse to find equivalents to the above? Recommendations here are also ok.
3. I saw that Firefox isn't exactly private(?) and that Vanadium is better in that aspect but I don't understand why. Can someone ELI5, and help me see if this is a relevant concern for me?

Thank you! 😁