My son attends at UK university. Will I get a get a 1098-T form? How do I record his expenses?

Universities will issue the 1098-T to the student.  If you claim him as a dependent, you may be able to claim the Education credits.  

Follow these instructions to enter the expenses: Where do I enter Form 1098-T (Tuition Statement)?

Q. Will I get a get a 1098-T form?

A. Probably not.  Most foreign schools do not issue them.  But, you don't need it.  In the TurboTax (TT), you can answer that you qualify for an exception. 

But there are bigger issues. First you need to determine if your school is on the Dept. of Education's (DOE) list of eligible institutions. https://www.irs.gov/credits-deductions/individuals/earned-income-tax-credit/eligible-educational-inst

To claim the more generous American Opportunity Credit (AOC or AOTC), the school must have a US Employer Identification Number (EIN or FEIN). Most don't. 

 You can still claim the Lifetime Learning Credit (LLC) if the foreign school is on Dept. of Education (DE)  list.

 Foreign schools can obtain a EIN and because of this rule, some are starting to do so.