Is there a way to select "track depreciation" of fixed assets you've already entered into QB? When I go to edit those accounts, I don't see the option to do it. Thanks.

in the chart of accounts you create the fixed asset account, and you also create a sub fixed asset account called accumulated depreciation for that asset.

I do it this way, but it is up to you

Fixed Assets

>> car

>> >> car cost
>> >> accumulated depreciation- car

>> truck

>> >> truck cost

etc

QB does not make depreciation entries, you have to first calculate the depreciation amount and then do a journal entry

debit depreciation expense

credit accumulated depreciation - [asset]