BLTouch help please

I finally got my new BLTouch installed on my ender 5 also got the new 1.1.5 board in. But I did it with Creality firmware that came with the BLT. I tried marlin but for one didn't know how to edit it and couldn't find a file to fit my needs. Now when I try to level the BLT it travels off the bed to the left. Any way do download and adjust the firmware that's on the printer now so I font have to change every thing in marlin? or is there a simple way to just get the probe to stay on the bed ?