Thanks for writing in!
To use Cornerstone on posts, you need to you need to assign the permission for that under X > Settings > Permissions > Administrator > General and select Posts, Portfolio. To learn more about permission manager, please refer following post.
Regarding portfolio, you can use Envira Gallery plugin and can be installed from X > Validation > Extensions. You will have to make some UI changes and some custom development work to mimic the layout you are looking for. Custom development falls outside the scope of support we can offer.