Dreamcast Noob

[RetroToad]

Hello everyone! always been an avid game and always wanted the dreamcast and it seems like now would be a good time to get it so Im asking you all for help, what should I be on the lookout for? any certain system thats better or worse than another? which ones can play CD-Roms, how can I connect it online? and what are some of the best games to get! thanks in advance!