First, all graphics need to be in vector format for the cutter.
Second, multiple colors is usually not an issue, as you should be able to select which color to send to the cutter (or you can select multiple colors to cut in a single job).
Third, if there is overlapping in colors, and you're wanting them to be separate, if the logo is in color, then cut colors separately if the end product is a multi-color decal. If you're wanting the decal to be a single color, then be patient because this is where the fun begins ... you will need to choose a design/editing software of your choice, and start to get to familiar with it. This will not be your last logo that will come to you in multiple colors, nor will it be the first design you come across that will need some editing. So get to know a software that works for you - Illustrator, Inkscape, CorelDraw, Sign Blazer, Vinyl Master, etc.