Please help me(the newbie)

Note that to send from Aspire you will need to install an appropriate post-processor — since you have a BitSetter please see:

see: Vcarve Pro and Post Processor - #72 by Beaucejim for further details.

Carbide Motion doesn’t accept DXFs or SVGs — you have to assign toolpaths in a CAM program and save the machine movement instructions as G-Code. Please see:

For a tutorial on letters please see:

https://wiki.shapeoko.com/index.php/Child_Name_or_Letter_Board