Good evergreen coverage can include plants like bugle (ajuga reptans), pachysandra, vinca minor, european ginger (asarum europaeum), euonymus fortunei “coloratus”, and a good deciduous ground cover is sweet woodruff. Ferns will look good there too.
Make sure you’ve got rid of all the brambles before you start planting up, It might be worth leaving the ground for a bit, to see what pops back up.