I was in the exploring blueprints course it said i needed to download a file that was a whole world for use in the course but i was in .RAR format and i can't convert it into an actual project in the editor how would i turn it into a UE4 project

It’s compressed. Get RAR to decompress it:

And BAM, first sale!

when I was doing the exploring blueprints course I needed to download a file from box.com and so I did and it was in a .RAR file type but I really don’t get how to turn it into a file that the engine would make into a project so I can carry on with the course

please help thank you

While the Everyone is correct and Win-Rar will work I would suggest using 7Zip over Win-Rar. It’s free and open source.

https://www.7-zip.org/

No need to worry about buying something when there is a perfectly good free alternative.