It is easy to add a photo to a page or an article.
In Edit Page place your cursor where you want the photo to go on your page.
Click Add Media.
Select the photo you want to add and click Insert into page.
Click here to read about how to add photos to your Media Library.
Staying in the editing area, click on the photo you have inserted and a panel appears (see image below).

These give you alignment options, but if your image is full size it will fill the page anyway.
Clicking on the pencil icon gives you additional editing options (see image below).

You can add a caption, for example.
You can also use the Link To dropdown list to link your photo to another website. Choose Custom URL from the list and then paste in the website you want the photo to link to.
Remember to click Update if you do make any changes.