Where can I find the replacements for this when I a finish with the included pack ?

You can find them in the mysmile store on Amazon. MySmile Teeth Whitening Strips, White Strips Teeth Whitening Kit, Non-Sensitive 14 Sets Teeth Whitener for Tooth Whitening, Helps to Remove Smoking Coffee Soda Wine Stain, Up to 10 Shades Whiter https://www.amazon.com/dp/B08GQK34KY/ref=cm_sw_r_cp_api_glt_i_ZTDX4E6B1SZEF1P6RHBY?_encoding=UTF8&psc=1

Do you use the whitening strips before, during, or after using the mouth light? Instructions are unclear.

When you use the whitening strips, use it together with the whitening mouth light, twice a day

Instructions are inconsistent. Do you leave strips in for 30 minutes but light only for 10 minutes? Or both only 10 minutes? Or both for 30 minutes?

You put the strips on . Then place the light and it would turn off automatically on ten minutes of been onn then I leave the strips on for an additional 30 minutes and its working pretty good .