I would suggest that you need your own test kit, so you can see what your water parameters are whenever you want, without having to rely on an LFS being open and without having to rely on the LFS staff member knowing what they're doing.
Liquid-based test kits seem to be more reliable than paper strips.
In your current situation, I recommend testing every day, and if your levels for ammonia or nitrite are over 0.25ppm, doing another 60% change (or maybe bigger, depending on how far over 0.25ppm they are.
When you can go a week without having to change water, then you can go back to weekly tests and changes.
EDIT: Having just seen your latest post, then just get ammonia and nitrite tests for now, then when money allows, get nitrate and pH.