57Gregy

Try the Songs forum here. Made for uploading songs for critique.

Check the inputs of each track.
I am in the habit of setting the inputs to 'None' after recording with both audio and MIDI tracks. 

Here I created a bus, F, routed some audio to it, exported it.
 

Welcome to the forum.
It looks like you may have had the TTS-1 General MIDI (GM) soft synth opened by default. Or perhaps the Microsoft GS Wavetable  GM synth in your computer. It depends on what the defaults were when you first installed Cakewalk by Bandlab and what you did to it subsequently.
Open a project and go to Insert at the top, Soft Synth and select TTS-1. Once it's open, check out the patches in it. There are sounds like Fantasia, Ice Rain, etc., which I believe are standard GM patches.
 

You can either check the Synth Property Page space in the Insert menu or click the synth icon in the track pane. I don't know about Serum in particular, but that's how it's done in most other synths.
 
 

Welcome to the forum.
Did you download and install the drivers for the audio interface?

So, following the instructions I pasted in above, I was able to get it to change pitch. Most folks here probably do it without even thinking, but it's new to me.
Make sure it's a Groove Clip. Open the Clip Properties on the left. Check the appropriate boxes. Get pitchy!
One thing I didn't anticipate was the default key(?) of A. I had to change that to C or it would play in a different key than it was recorded.
 

I think you mean the 'Scrub' tool. That will allow you to drag the cursor across a clip and hear it. Hit the J key on your computer keyboard and the cursor will change to a speaker icon and you can then scrub by click-dragging. Hit J again to turn it off.
I don't think you can enter just the chord letter. I just tried it and it always placed the chord diagram above the staff. You then would have to right-click that diagram to navigate to the chord you actually want (it defaults at 'C').
You can, however, use the Expression button and type in your chord letters, but they won't be above the staff but below it.