Hi. Live in NJ, work in NY(C). Does this mean Under the "New York Income Allocation" section, the "New York Source Portion" of my income is all of it?

You should not need to allocate anything ...

You must file a non-resident NY tax return in addition to your home state NJ tax return.

You'll be able to take a credit on your NJ return for taxes paid to NY, so you won't be double-taxed.

In TurboTax, be sure to complete your non-resident state return before you do your home state return, so that the credit flows properly.

See this FAQ for more detailed instructions:  https://ttlc.intuit.com/questions/1901271-how-do-i-file-a-nonresident-state-return

If you worked only in NY, the "New York Source Portion" is 100%.