I need a newsletter template designer

I work for a cyber security company. We are creating a customer newsletter to go out to all of our vendors via email. I would like 10 pages of something clean and uniform that I can fill in with information. With a similar visual concept to other cyber security newsletters. I can send over the color codes and fonts that would need to be used. I would like it to be compatible with canva or easy to fill in. I attached a few examples of newsletters my boss likes.