Ozz
You will figure this out YET!
The large size you are being told about. Do this. Place cursor over a photo, I chose the top one, with light hanging out of wall.
While cursor is over it, right click on your mouse, it will give you a list of choices, go to PROPERTIES.
You will see that the properties for that one photo are 91765 bytes. That is rather large for the forum, half that would be at the outer limits. (For those on cell phone connections, these would take forever to load, been there, done that, will do again! HA HA)
On my web pages, I try to get the bytes on a single photo down to around 15,000 to 20,000. I have on occasion gone a bit larger, but I try not too.
I have never used photobucket, so cannot help you there. I use Adobe Photoshop for my photo reducing, editing, fixing, etc. I'll bet your computer has a program like Adobe, maybe the software that came with your digital camera??
Good luck, you are getting computer savy, just a bit further to go!
Carol