@Don Von Alpha Dom
I've spent the last couple nights learning SL and setting up an avatar and diving into the sex products (which are not only legal but super easy to get).
I'll just re iterate what
@KokoNyny
said, clothes can be purchased in one of two ways:
1. You can purchase them from the website catalog just like in IMVU. (
https://marketplace.secondlife.com/)
2. You go to a 3d marketplace (sort of like a room on IMVU) and interact with the products in world.
I've only purchased 1 product so far but I've made an entire (somewhat decent) avatar, there are lots of places in world where you can get freebies.
I also agree that you should switch download firestorm. It's much better than the "vanilla" viewer (as they call them).
I will say this though, IMVU has a better shop, inventory, and dressup interface. SL uses really outdated looking UIs and the UX is kind of terrible. But SL offers WAAAY more functionality in terms of customizing your avatar. You can editing products (moving, scaling, etc) in world instead of a separate mode. So if you buy a dick for example and you don't like where it is, you can put it wherever you want, even your forehead if you so desire. You can even change the body shape from butt size, shoulder width, leg length down to package bulge and even body fat.
But overall IMVU is way more user friendly if you can believe that. It's a tad easier to navigate through the client and while it's not as feature rich I do believe it's easier and quicker to get a good looking avi as you can just buy a body, head, etc.. instead of having to fiddle with sliders or find the right products that work with the baked on meshes you have equipped.