Amazon S3 Bucket slow, Cloudfront does not help, wrong configuration?

Hi there,
please be patient with me on this one, even if it is in fact a basic thing. I am a total beginner. I am sorry for that.

For a magazine app we host content on a S3 bucket. Using S3, a file of 50 MB takes around 10 to 15 minutes to download. This can't be right. Shouldn't this take only 30 seconds or maybe a minute depending on my downloadspeed?

So I was told to activate Cloudfront to fasten things up. I did follow the instructions in the documentation, activated Cloudfront, but nothing changed. The support of our magazine-provider told me to ask the following: "We have activated CloudFront at our end for two of our buckets. But when we fetch the files stored, we are not yet receiving the CloudFront URL. Please let us know if we are missing anything and what all needful is to be done."

Could it be that I need another URL to fetch the content? Right now, I am using this one:

https://s3.amazonaws.com/schwaebische-magazin-us-northvirginia

I hope to hear from you soon and thank you in advance, Michael