how can i earn points so i can upgrade my gallery ?

or do i have to pay for that ?

i'm getting this message :

The size of all the pictures is higher than the allowed limit. You cannot send more

or can i re size the images so i can fit more on my site ?

You need to buy the points to expand the capacity of your gallery. You can buy points by going to admin panel=>Misc=>Points Management=>Configuration and click the "Buy points" button. After you have enough points click the "Modify" button next to this message "You dispose of 10 Mb of storage for your gallery"