Hello. If you’d like some help from your fellow GF users you might consider posting your output file (SVG, PDF) or, and it will be a smaller group but you’ll still get help, your original Coreldraw file.
If you’d rather not do that there are several items in the Glowforge Tips and Tricks section that talk about preparing files for the GF. I’m pretty sure Coreldraw is one of the software packages covered. Check the “matrix” to find specific articles.