I'm a new member trying out your company and setting up

I'm a new member trying out your company and setting up a site to test your software out. I picked one of your themes to use. First off, is there anyway to use visual composer instead of upfront? The upfront software is not that user friendly for me.

The first main issue I'm having is that every time I go to edit the main slider at the top of the page, it locks up. I click the + sign to add slider and the screen goes blurry and it doesn't do anything. Then I try to do something else and it says can not do that while uploading media yet no screen came up for uploading media.

Is this a problem with Mac users? I'm using chrome on my mac. When I get home, I'll try this all on my PC but trying to work remotely is a must for me.

Thanks for your time