Hi, you have 4 bottom positions: bottom1,bottom2, etc. So if you want to publish two modules publish them for example in 'bottom1' and 'bottom2' positions.
The bottom1,2,3,4 and top1,2 module positions are prepared to show up to 3-4 modules - please just publish more than one module on the module position and then you will get two or more columns of the modules.