Please help with my transmission

[67Vega]

Hey guys, so I recently replaced my working harness on my 67 GMC C1500 truck. She turns over and runs semi fine, but there are 2 connections that were left with nothing connected to em. The first one is on the transmission, it's on the left side in the middle of the tranny, single prong. I don't know what it connects to. The second one is under the carburetor, and it's a 2 prong connection. I also don't know what it connects to. And lastly, I replaced the steering column on it, and I can't get it to shift right. Neutral on the column is reversed on the transmission, Drive is nuetral, and 2 is Drive. Also, reverse lights come on while not in Reverse for the transmission, comes on between Nuetral and Drive on the steering column. I've pulled the shift fork all the way up into the Park position, and secured it to the steering column all the way up in the Park position indicator. Nothing is working with it. What can I do to fix this issue. Thanks in advance. Also the transmission is a TH400.