A P0700 is just a generic "something is amiss in the transmission" code, that's not an actual transmission code which requires an aftermarket OBDII code reader to be able to read. The P0850 says something is wrong with the Neutral Safety Switch which is there to prevent starting the engine unless the transmission is in Park or Neutral. That can often be caused by nothing more than the transmission shifter cable has stretched slightly so the shifter isn't quite putting the Neutral Safety Switch into its Park or Neutral position which can cause you to need to pull the shifter slightly between Park and Neutral to get it to start.
First, your Profile is empty so what model year do you have? Second I would check the transmission's ATF level to make sure it's not just low on ATF. If it is low add enough ATF+4 (nothing else is correct) to the transmission via a small funnel inserted into the transmission's dipstick tube.
This is how to check your ATF level, and it must be checked exactly as described or you'll get an erroneous ATF level.
For a 2002 or older TJ check the ATF level while the engine is running and the transmission is in Neutral. The engine MUST be running and the transmission MUST be in Neutral for 2002 and older TJs.
For a 2003 or newer the engine must be running too but the transmission can be in either Park or Neutral.
Where an automatic transmission is concerned it's far better for it to be slightly overfilled than even slightly underfilled. No, slightly overfilling an automatic will not harm it like overfilling the engine's crankcase can harm the engine.
