It might be best to get a collection CD and see which artists you like,

A CD called "A Rough Guide to Bluegrass" is quite good and should be fairly easy to find on eBay.

The older "first generation" bluegrass artist used guitar only as a rhythm instrument with mandolin and banjo taking the lead breaks.

Later "progressive bluegrass" often has an electric bass replacing the "dog house bass" of traditional bluegrass and jazz.

Tony Rice and others turn bluegrass into a showcase of brilliant guitar work, something I like but Bill Monroe did not like at allow.