Yep, the others provide good advice and I agree with it.

Amounts for umbrella coverage just depend on your personal situation and the amount of assets you have/own. Obviously, the more you have, the more umbrella coverage you want to get.

No reason to hold a multi million umbrella coverage policy if you have little assets, IMHO. Coverage is very affordable these days.

I do think you can buy stand alone coverage but most places will ask you to have minimum amounts on your car, home, etc. as flu mentioned. It’s always cheaper to bundle it all together.