my car when i sit in it turn the key the dash goes to the D.

I had this happen once! Looked under the hood and the little round plastic ball looking joint had popped out of the shifter moving arm. Look there, driver’s side down at the end of the arm. If not the problem, see if you can bypass the safety switch that keeps you from starting unless in Park, you can start in Neutral at least if you can in fact bypass it. Your car thinks it’s in Drive, because possibly it truly is and it only looks as if in P or N on your gear selector or possible sensor is bad saying you’re in D when not. Linkage bad another possibility. Let us know please what it is you find out

I came across a post where someone removed the plastic cover over the gear shift selector and bypassed the safety switch. You may need to check there as well.