This web part automatically shows recent activity on your site, such as files uploaded, edits made, lists and libraries created, and so on. Just add the web part, and the latest activity is pulled in automatically.
Add the Site activity web part to your page
If you're not in edit mode already, click Edit at the top right of the page.
Hover your mouse above or below an existing web part or under the title region, click , and then select the Site activity web part.
To change the number of items shown on your page, click Edit web part on the left, and enter a number in the toolbox under Show this many items at a time. Then click Apply.