It seems like whenever I try to upload a photo for my account avatar it's not accepted and I really don't understand why if somebody could help me that would be awesome Thank you

at a guess 
its either your file size is to large (to many mb) or the picture contains something thats getting flagged as inappropriate  

tried a small image 200px x 150px (width x height) at 95kb - worked without issue
tried a larger image 1200px x 670px (width x height) at 2.2mb - worked without issue

I couldn't find the image that I originally wanted but it seems this one is smaller and it works just fine so thank you