Re: Complete newbie!!! Help on the basics.
If you’re going to create a theme from scratch, then you definitely want to use the child theme so that it’s ready for the next time you have to upgrade BP. Although, the default theme is a good place for you to start since it uses all of the BP features and you just have to change the style, layout, etc. Or you could find an open source BP theme and just adapt it for your needs as well.
Otherwise, you can download the BuddyPress Template Pack which will try and convert your current WP theme into a BP theme. No doubt in this process of converting it to a BP theme, there will be changes you’ll need to make to make your old WP theme display right with the BP components layered on top.
Word on the street is that either option takes about the same amount of time. Kind of depends on what kind of WP theme you have already. Otherwise, probably better to just create a child theme.