Want to help my lovely father

Hi,
I join this forum on behalf of my father.
He is 80 years old and healthy until 2 weeks ago I toke him to the hospital for checking something growing near his neck. Doctor did a biopsy and found out it was a carcinoma metastatic, so they checked his lung and they found out the premier ca in his lungs, it's around 4,5 cm, NSCLC, metastatic, they said. Doctors made a blood test and scan on liver and kidney, result : Kidney and liver are still good but there's CA already in blood. They said my father is in stage 3b. They suggest to give my father 1st treatment ( 2 times injections, each in 3 cycle , don't know what this mean actually). We are afraid of this chemo as we heard its so painful.  His tall is 170, his weight is 54.My questions is:
1. What is the best threatment for my father with his stage and age?
2. I heard about cryotheraphy, is it good for the man on his age?
3. How to reduce the spread to throath and brain?
4. What kind of food he should really avoid? can he still consume salt and sugar?
5. Is it possible to have a surgery?

Pelase give us advice as we really don't know what to do and we afraid of chemo.

Thanks

Grace