If you are new to Embroidery and have a program that will help you edit your fonts and resize, you have everything you need to create a custom monogram or name. Different programs operate in different ways, but the one way that most programs can be guaranteed to work the same is by clicking the "File" tab under your programs header bar. Scroll down and then click "Merge Files". It should then give you the option to upload a new letter of your font to existing font or blank page. You may have to simply start the program by clicking on the font letter to have the page opened with the letter in the center of the screen. Then you can go to File and click down to Merge Files or something of the like.
Once your letters are in the correct format, you can re-size each letter according to your needs by clicking on them and then dragging the surrounding box according to the size desired. I have a preference to Embrilliance Essentials for this particular feature because it recalculates the stitches for you and fills in where needed as you adjust the size of your font.
Just remember that your combined design or monogram may not be larger than 3 13/16" wide or high for a 4x4 hoop or it will not load on the machine.
4 13/16 x 6 13x16" on a 5x7 hoop
6 13/16 x 11 13/16 on a 7 x 12 hoop
There are endless possibilities with a good editing program. Hope this helps answer some questions!