Will 16in wheels and tires fit on a 2014 ford focus titanium?

Reason I ask is because the se model comes with 16s, but our titanium model came with low profile 18s. But like if I go to walmart.com it only gives a choice of either 17s or 18s.

Yes, absolutely.

http://www.tirerack.com/tires/OptionalTireSize.jsp?searchDiameter=16&autoMake=Ford&autoYear=2014&autoModel=Focus+5-Door&autoModClar=Titanium

If you have 18 inch wheels, you'll have to use 18 inch tires. You can't mount 16 inch tires on 18 inch wheels. You can get 16 inch wheels for the car though, if you get a set of 16 inch wheels then you can use 16 inch tires. But it would be cheaper just to get 18 inch tires.

Pro tip: Don't buy tires from Walmart, some of the tires they sell are made by tire manufactures you know, but some models are built to Walmart's price and aren't sold anywhere else other than Walmart/Sams Club, and aren't even warrantied by the tire manufacturer. That should tell you what you need to know about the quality of some of the tires walmart sells. For example if you buy a set of Goodyer Viva 2 tires from walmart, you'll notice they aren't listed on Goodyear's website, and they aren't sold anywhere other that Walmart, you'll also notice that Goodyear doesn't warranty those tires, Walmart does. If you have an issue with those tires and try to have a goodyear shop fix or replace it, they'll laugh you out the door.

It's unwise IMHO to cut corners with tires or brakes.

Stock OEM wheels? Yes