Hi @ShenitaDi

Creating Photo Gallery page is simple. Please follow these steps below :
1. Go to Admin Panel / Pages / Add New. Then create a page name it “Gallery”.

2. In your Gallery page click Add Media button just above the content editor section.
3. Then appears a new window. On the left column of this panel select Create Gallery.
4. Upload new images or select the existing ones and click Create a new gallery button on bottom right of the panel.
5. Opens up a new panel, select Attachment Page option in Link to settings. Select no. of columns, image size , etc according to your design and requirements.
6. Then click Insert Gallery button. You will get the shortcode inserted into your content editor. Give this image gallery a title for e.g. My gallery

It looks something like this:

My gallery

[gallery link="file" ids="770,769,768,767,766"]
You can create more galleries under different titles by repeating same steps as above.

Hope this will help to resolve your issue.
Feel free to post if any confusion.

Best Regards!!!