Hello there! I am new to this website and so please forgive me if someone has already asked this question as I'm having a bit of difficulty navigating the website.

I want to submit a work of art to the monthly online competition but every time I try to do so, either the file size is too large or it is not in the right format. What are the limits for the file size and if the file is too big, how do I decrease its size? Also, what is the correct format? I have been trying to add photos of my work that are in jpeg format but that doesn't seem to be the correct format. Any help would be greatly, greatly appreciated!!!
Thank you so much in advance!
Ashley