Long time Risk player, but got destroyed in my first game. Definitely need to become more familiar with the more popular boards.

(Also, having trouble changing my profile image. It doesn't allow me to upload a replacement.)

Welcome notbad! I (we) hope you enjoy your time here. if you have questions, feel free to ask; most are welcoming and more than helpful.

As to your 2nd problem first: if you were unable to re-upload a new image (Profile, Edit image on the left) then it may be a premium member ability (i just tried it and it worked, but i'm premium). I don't have a full list of premium perks memorized anymore. But we could probably find someone who will know for sure. 

As to the first, Civil War is  one of the more difficult beginner boards (it's large with a number of choke points). There's a couple of ways to go.
1) You could filter on the easy boards (Board tab and click on All Boards icon then the Easy/green light icon -- you can tell if they are active if they have the small yellow border around the icon). If you want images of what I'm talking about I can do that. 
2) you could try some specific examples of easy boards that some of us grey beards recommend (it seems that the forum search isn't working well right now -- damn google always changing their algorithms). I can try to list a few a bit later.

let me know what you think; i'll check back later when i get some time. 

Also Welcome!

Most of the people you play with on this site have been around for awhile so know the ins and outs pretty well - so don't get too discouraged - as wt said most/almost all of us are very helpful -

There are a number of modified rules that show up on different boards that really change the dynamics of play - Return to attack from placement/fortify being perhaps the biggest - but there are many more. So, read the rules tab for each board and ask if you don't understand what it is saying.

I see you are in Vikinger - that is fairly popular these days and a fairly straightforward map (though with border modifiers) so that is a good choice.  

I am quite sure anyone can change their profile - so there is something going on there. tom is our admin/benefactor - if you cannot figure it out then pm him.

Also, the Civil War board is absolutely horrible at anything less than Medium fog.

Welcome notbad :)

Civil War is not one of the easier boards. I see you're now in Wargear Warfare as well as Colossal Crusade, in addition to forementioned Vikingr. Those are good choices. Many start there, many stay there. I hope you'll get the hang of it and enjoy the games :)