Tempo is often measured in beats per minute. A time signature tells you how durations are grouped.
In 4/4, the top number means four beats per measure. The bottom number identifies the quarter note as the beat unit. A bar and a measure are the same thing.
In 3/4, there are three quarter-note beats per measure. In 6/8, six eighth notes are commonly grouped into two larger beats, each lasting a dotted quarter note.
Keep a steady pulse and vary where your notes begin and end. Rests, accents, and repeated rhythms give a phrase its shape.
Pick up your guitar
Use A minor pentatonic. Count “1, 2, 3, 4” steadily and play only on beats 1 and 3. Then change the rhythm without changing your notes.