iMac

Hi Everyone, I'm really new to all this.  I've played with Blender on my laptop which runs Windows but now I'm trying to get it to work for serious on my new iMac.  I have to create some sculpties for the work I'm doing in Second Life.  However, I keep running into problems with setting it up.  I'm not a programmer so please be patient with me :-)  I can get the Import/Export to show the Second Life options and I can get the Build menu to come up when I request Add> Mesh> Sculpt Mesh.  When I get the Build menu, even if I change nothing in it, the screen