Hi! You can find the procedure for creating the portfolio thoroughly detailed in your Theme Documentation. Let us know if you have any specific problem with creating a portfolio page with that process!
HI! Firt of, you need to creat your portfolio page, ase you named before. Afterwards, you can start setting up the galleries inside the portofolio in the Portfolio Section of your Theme Options Panel. Afterwards, you need to Edit Portfolio Entry, set it up as you wish and then click on Publish