How do you make a map scroll with your controlled sprite on a top down view map? And how do you do BG collision?

idk scrolling but for bg collision you make 4 variables canleft, canright, etc. make it so to move those directions the variable or the direction needs to be 1. Do col=bgget and if col=tile value found in smile then direction you are facing variable =0 then if false variable = 1.