In case you got 404 pages instead of the portfolio item, please, go to Settings > Permalinks and click save.
Permalinks are the permanent URLs to your individual weblog posts, as well as categories and other lists of weblog postings. By default, the WordPress permalinks had plain structure, with numbers
Before displaying the portfolio items in Portfolio module, you need to create portfolios in the corresponding section of the admin panel. Check the Portfolio item creation section of the theme documentation for more information.
Portfolio section is the perfect way to present your projects and creative ideas to the whole world. Check this post to learn more about Portfolio page creation. Base portfolio options
Portfolio item post type is the perfect choice for demonstration the creative projects for your visitors. To create a new portfolio item, simply navigate to Portfolios section of the admin area and
To create Portfolio page, you should navigate to Pages section of the WordPress admin area and click on Add new. Select Portfolio page template for your page in Page Attributes