First head to the section where you can edit templates, refer to these videos for help getting there. Once there, find your photo you want to add a link to, select it, and a panel will pop out of the left side. In the panel there will be a link that says “Link” next to the thumbnail of your photo, click there. A window will pop up and you can add your URL or other link to the photo.
To link text, find the text you want to link, select it, and a panel will pop out. In the panel, highlight the exact text you want to link. Then locate the Link icon (looks like a chain link), it should be right next to the U symbol. When you click the icon a window will pop up and you can add your URL.