There are two ways: 1 easy but doesn't always give desired effect and 1 a little more time consuming but allows for more creativity.
Once you have your text typed then under the Edit tab you can use the "Letter Spacing" toggle to bring the letters closer, but it will bring all the letters the same amount of closer together (not proper English but you get the drift) which can sometimes cause overlap that you don't want.
The other way is to use the button on the Edit menu that looks like an Ei but with boxes around it (this should be under the Right Center and Left align buttons) and when you hover over it says "Isolate Letters." This will separate all the letters and allow you to move them independently. The downsides to this method, once they are isolated you can't change the font unless you click undo and if you resize one letter it will not resize the others unless grouped together.
I prefer the second method as it gives a better look but recommend resizing to the size you need before isolating the letters. Then once you have the letters positioned where you need them either group the letters to resize or if you know you will not need to adjust anything about the individual letters and they are all to be the same color you can weld them together. Again time consuming but I think worth it for the end product.