You will enforce the laws that congress gives you enough money to enforce, which ain't enough to deport anywhere near all the illegals in the US.
Not having enough money, you would likely concentrate on the low hanging fruit, the ones that are the easiest to catch, which are the ones living openly, showing up to protest.
Unfortunately, the ones we need to be deporting are hard to catch and deport.
Oh, I’d just transfer money from the Dept of Ed and the Dept of Energy and the EPA — I’d have PLENTY of money to deal with illegal immigrants.