Software Problems, Alot of Them. Want all help possible!

Hello my name is Max (Quick disclaimer this is my first time on the site so sorry if the thread is in the wrong place but i couldn't find any other)
For christmas I got a Delta Kossel medium sized printer (Basicly a bigger Mini), me and my dad managed to complete the building part of it in about 3 days but since then I have not been able to fix the software at all.

I need help with calibrating it.

I have tested 4 different versions of Marlin, and I am using pronterface along with that. In the Marling that followed with the SD card that we bought the G29 code goes to the completely wrong z axis and is trying to hit the build surface around 50 MM above it, and then fineshes of 5 mm above it just to later when you try to move it go nuts upwards becaouse it thinks it's too low after the auto bed leveling.

I found another copy of marling that had Kossel settings preconfigured into them, but whit that version the LCD screen stops working and just shows squares. And when I try to use G29 with this version it only hits the print bed with the nozzle on one side of it super hard and sounds really wierd but falls short and misses on the other side which follows up by an error in pronterface :

SENDING:G29
G29 Auto Bed Leveling
-10.50 -10.50 -10.50 -10.50 -10.50 -10.50 -10.50 -10.50 -10.50
-10.50 -10.50 -10.50 -10.50 -10.50 -10.50 -10.50 -10.50 -10.50
-10.50 -10.50 -10.50 -10.50 -10.50 -10.50 -10.50 -10.50 -10.50
-10.50 -10.50 -10.50 -10.50 -10.50 -10.50 -10.50 -10.50 -10.50
-10.50 -10.50 -10.50 -10.50 -10.50 -10.50 -10.50 -10.50 -10.50
-10.50 -10.50 -10.50 -10.50 -10.50 -10.50 -10.50 -10.50 -10.50
-10.50 -10.50 -10.50 -10.50 -10.50 -10.50 -10.50 -10.50 -10.50
-10.50 -10.50 -10.50 -10.50 -10.50 -10.50 -10.50 -10.50 -10.50
-10.50 -10.50 -10.50 -10.50 -10.50 -10.50 -10.50 -10.50 -10.50
Error:Z-Probe failed to retract!
[ERROR] Error:Z-Probe failed to retract!


Error:Printer stopped due to errors. Fix the error and use M999 to restart. (Temperature is reset. Set it after restarting)
[ERROR] Error:Printer stopped due to errors. Fix the error and use M999 to restart. (Temperature is reset. Set it after restarting)

Also, the Z axis is really inconsistent depending on if it is close to a tower or in the center, we had It setup so that the center coordinates where perfect but then when we tried the croners theey where about 5 mm too close to the bed. And when we fixed the sides by manipulating the endstop positions the center bacme about 5 mm too high instead. We tried to fix this simply with the M666 command but for some reason it does not work for us. And we cannot find any place in marlin where that actually does any difference.

I appreiecate all the help I can get since I am very in-experienced with 3D printing over law.
Thanks lot, Max.