Park on Cains Lane the next road down thn walk back to Myrtle, take you 5mins, easy peasy!

You could try Myrtle Avenue itself, as there is a very small (2 space) car-park right up next to the field where you will be viewing from…with you arriving fairly early, you may find a space free there, but with it being a Saturday, it would all depend on whether the local residents use these spaces to park their own cars at this time. Otherwise Cains Lane is your best bet as mentioned above!