Here there are four six eight time signature exercises. Pay attention to intervals, ties, slurs and fermata. You can see in the image on the right examples of six eight time signature bar patterns. 

There is the exercise sound and a metronome sound for exercise1 to help you follow the beats.. You may check some online metronomes to help you increase speed while you are rehearsing: metronome 1, 2, 3. Don't worry if the links are not working, all you have to do is using your search engine to find an online metronome. 

First study the scores and practise hand movements to represent the corresponding time signature. Then name the notes aloud while keeping the beat with your hand. It doesn't matter if you start slowly, the idea is that speed is increased with practice and the metronome sound.