@komododragon2002
Register an account on imgur.com
If you're on windows keep following. If you're on osx just reply to me and I'll tweak this for mackintosh.
Place your finger on the windows key (looks like four squares) and while holding down the key hit r, this should open up the Run prompt.
Under Run, type %appdata% and then hit enter. Open .minecraft and scroll down until you see a folder named screenshots. Open this folder and move the screenshots you wish to upload onto your desktop. Make a new folder called "Skywars Map Pics" or whatever you chose to name it, and just drag all the screenshots from the desktop into the folder. Now when you long into imgur select Upload Images (top left of screen) and then choose desktop. This should open a prompt to select your file. Open the folder you kept the pictures of your map in (on the desktop), select the ones you want to upload, and then tap the enter key. Once you've uploaded them select the imgur link on top of your search browswer and copy/paste it into your original message.
Hopefully this helped, if not let me know and I'll message you a few alternatives.