Can someone please give me a simple answer?

The transition is the difficult time. For some time you need to run both systems in parallel...unfortunately.

I was also a Corel user for years (I used even one of the first Corel Draw versions...), but as Adobe products are the industry standard and we had multiple problems with our print service providers, I decided at some point to switch my people to Adobe. We kept our old Corel licenses but after a couple of years, and with new computers, I decided that we drop Corel completly. We still would have, however, access to our old Corel Draw install disks. But for about 10 years, we did not open one old file. I even can't remember the exact version of our Corel install.

This said, I was able to do anything in Corel and I'm having still problems getting to the same productivity with Illustrator. Fortunately for me, I'm no more the guy who needs to do the fancy stuff. I can delegate to younger ones and in the meantime the Corel veterans are in a minority...

It looks like you have a Corel subscription? I would buy Corel Draw essential just to have the program to convert my files as needed. Your new work can be done correctly with Adobe Illustrator.  Old Corel files can be converted to Ai, PDF or EPS or SVG, what ever is best in your case, and then opened in Illustrator. Alternatively you could try Inscape, as suggested by Nancy, as an in-between as it claims to be able to open CDR files:

What formats can Inkscape import/export?

Inkscape natively supports opening or importing many different formats, such as SVG, SVGZ (gzipped SVG), PDF, EPS, and AI (Adobe Illustrator) formats. And, as of version 0.91, Inkscape can import CDR (CorelDraw) and VSD (Visio) natively.

It's not a technical question, it's a principal problem. As industry leader, Adobe Illustrator needs to do virtually no effort to open different file formats. So the only "foreign" file format left over is Autocad...because Autodesk Autocad is the leader in his environment.

I'm a long time Corel user too, but I have to use Adobe for my day job.  Unfortunately, Adobe has decided to not include any kind of support for opening CDR files, and your fountain fills and power clips won't show correctly.  Corel can open AI files just fine, but Adobe must have decided it was more profitable to make it as hard as possible to use Corel products.  You can save it as a pdf from Corel, but that's still buggy.  TBH, your best bet is to find someone with an edu email and get the student version of Corel - I paid $99 for the technical designer package because I still qualify for a student discount.  

Perhaps this thread will help?
https://community.adobe.com/t5/illustrator/is-there-a-way-to-open-cdr-corel-draw-files-in-illustrator/td-p/7752444?page=1

What file types did you create in Corel Draw?

• Raster image files like TIF, JPG, PNG, GIF, BMP can be opened in Photoshop.
• EPS, PDF, SVG and SVGZ can be opened in Illustrator. 
• Also PDF can be opened in Acrobat.

Do you have Inkscape, the open source vector graphics app?  I think Inkscape can natively open Corel Draw files but I've never tried it.