Stalling and difficult to shift the transmission into gear and speedometer not working

This might be more than one problem. To be sure let's do a CAN scan which is the future of automotive repair you can get a CAN scanner from Amazon for about $50.00. here is a video to show you how and a link to a scanner from Amazon:

https://youtu.be/u-4syLc-ifQ

and

https://amzn.to/3OpAotj for the scanner

The speedometer problem can be what is causing the issue.
With Antilock Brakes

This vehicle does not have a "Vehicle Speed Sensor" Component. For diagnosis, please refer to testing for these systems:

- Antilock Brakes (ABS)
- Body Control Module (BCM)
- Powertrain Control Module (PCM) See: Computers and Control Systems > Testing and Inspection
- Information Bus
- Instrument Cluster See: Computers and Control Systems > Testing and Inspection

Without Antilock Brakes

For diagnosis please refer to: See: A L L Diagnostic Trouble Codes ( DTC ) > Manufacturer Code Charts > Vehicle Speed Sensor Failure

Here is how to test the speedometer to see what's going on. Check out the diagrams (below). Let us know what happens and please upload pictures or videos of the problem.

I think this is what you need to get the relays and fuses installed. Check out the diagrams (below). Please let us know if you need anything else to get the problem fixed.