You can make characters jump without GML; check out the Platform tutorial at
www.yoyogames.com . The tutorial really helps, I'm making a platform game right now =p
Screen scrolling is easier, in the room that you want to scroll click the 'Views' tab, tick "Enable use of views" and "Visible when room starts", then set "View in room" to your screen size, set "Port on Screen to your room size too. For "Object Following" select the character you want the screen to scroll with. Set "HBor" and "WBor" to the room size and "Hsp" and "Vsp" to the speed that your character moves.