So you need to teach your right hand were the strings are. So spend a little time just working on it. If you choose of course, going down play A, D, B. On the way up E, G, A. Because you also need to work on timing, I suggest you tap a foot each time you hit a string. You know the routine start slow and build speed. Maybe single pick going down and double on the way back up. Spend 3 to 5 minutes doing it, then do something else for 10 to 15 minutes, then just the right hand again. Repeat if it helps and mix up the patterns.