Practice both at home and with other people. Most rock and blues stuff is in 4/4, meaning the rhythm is 1,2,3,4 over and over. 3/4 is 1,2,3 over and over. Clap your hands or count to the beat of the song and you'll get it. I think it is a ratio of beats per measure or something like that. Metronomes are excellent, but you should also play with other people and jam along with recorded music, e.g., the radio, cd's, etc.