how to insert portfolio/project page in 2017

Hello!
I am customising ‘twenty seventeen’ for my freelance work, I wanted to add portfolio (gallery).
I found ‘portfolio’ option in panel, and created projects also added it in menu but unable to add portfolio work in it?

check the link please: https://crosswalkadvertising.wordpress.com/

Can anybody help me how to add my portfolio in gallery format

Thanks a billion in advance ??
CW