Welcome to the Forums, Oddguy. Those logos are called banners (I think that's what you're talking about). You can either make one yourself (in which case you need to obey the
rules on banner size) or ask in the
appropriate topic.
The stars and 'Slurgs' are statuses and ranks. They change depending on how many posts you make. But don't let that be an excuse to spam. Check how the ranks work
here.
Have fun