Andrew designed a personal fitness program two months ago. now his workout seems too easy, and he is bored and no longer progressing. which training principle should andrew take into consideration?

Progressively Overloading his muscles, assuming he is doing weight training, to increase strength over time. he should not stay with the same weight for two months, unless he can perform more reps with better form over time.

You did not show us the image of the burger, but i shall try to answer as best i can.  when purchasing food, always consider the ingredients as well as the person who prepared it. consider if they were hygienic people or not, in case the burger was infected with bacteria. no mortal should place an infected burger into their mouth.