Hi Greg and welcome.
You join at a moment of much confusion and excitement as the site is undergoing a major rework, and we are all having to learn new ways of doing things.
So your question about creating your gallery is not as simple as it might otherwise be.
The new site design includes an extensive range of features that can be used to adjust the way a gallery appears, but I would suggest initially that it is best to keep it simple.
In the menu at the top of the page (in the black bar), pull down the "Portfolios" menu and select "Upload Pictures" - then on the screen that now appears proceed as follows:
"Choose a category to upload your images to" ... I suggest you leave this at the default setting of "Portfolio Member List"
Select the photos you wish to upload from your computer: Browse to the image file on your computer that you would like to upload, and select it.
You can enter a default title, descritive text or keywords if you want, but these are not essential.
Press the submit/upload button.
You will be redirected to the next screen where you can edit titles and other details before uploading, but when you are satisfied just press the process button and your image should be loaded into your gallery.
Repeat this procedure for other pictures.
Finally - I am not sure what the size limit and number of pictures allowed limit is for free members. Perhaps someone else will provide an answer to that one.