Welcome. Seems like everything is medically set for your treatment, which is pretty standard chemoradiation. Everyone is different in how they respond to, and recover from treatments due to many factors, including amount of radiation, areas radiated, amount of chemo for body weight, comorbities, age, treatment center, but there are some very common ailments we all endure, and some more unusual than others. You will probably be sent to see a speech and swallow therapist, nutrionist, and dentist prior to starting, if you did not already, all of who are important. The speech and swallow therapist will give you exercises to do, nutrionist about eating an adequate diet, hydration for your body weight, and dentist checking your teeth, correcting cavities before radiation, giving fluoride trays, prescription fluoride, and sometimes mouth guards, amongst some. If any teeth are extracted, two weeks healing time is needed before starting. Also as mentioned, all the baseline testing, including an eye exam, which can be effected by treatment.
I did not go into my initial chemo induction treatment with a peg tube, a port yes, but a peg was put in when I was hospitalized afterwards, and barely remember having it done, but could not do without one for any subsequent treatments.
Something not often thought about are future needs for medical insurance, and employment, in case either one ceases or need time off for a longer duration. It may best to see what your work benefits are ahead of time for sick pay, FMLA, short term disability, etc.
The same for medical insurance, knowing your co--pays, deductibles, hospilization deductibles & limits, prescription costs, physical therapy, occupational therapist or speech and swallow therapist.
You may want to set up a filing system since the invoices, coverage letters are sometime unrelentless. I have one for every doctor, hospital, including copies of all tests done, cd's for future reference, which I needed often, and obtaining them afterwards can be inconvienant, and costly.
Good luck with everything, and may have more questions as you proceed further.