The minor pentatonic scale can be played in any key. The following diagram shows the open position fingering for the E minor pentatonic scale. Notice that this is the same as the A minor pentatonic from the 5th fret moved down so that the nut replaces the first finger, resulting in open string notes being used on all six strings.
Here are some licks derived from the E minor pentatonic scale. Learn them from memory and then use the ideas to invent some of your own licks. Blues players often improvise licks when they are playing live, so the more practice you have at this, the better.
Here is a solo in the key of E which contains a riff and some connecting licks derived mostly from the E minor pentatonic scale.
As mentioned previously, it is important to experiment with the riffs and licks you have learned and create your own from them. This way you will never be short of ideas when you are playing with other musicians.