your probation may be extended for an additional length of time. you may have to serve some time in county jail. you may have both punishments assessed upon you.
remember, while on probation you have to follow ALL of the conditions. you say you have some side jobs, that's good. however...
the problem you face is that the edge of the parking lot was an open and obvious danger. you saw that there was no block or curb to prevent your truck from rolling off the edge.
Why did you back into the slot instead of driving forward? While backing you obviously were not able to determine...