/diy/ - Do It Yourself

I am not knowledgeable with circuits or voltage or watts or amps or anything like that. But I have done some research, and I -think- I have everything I need to complete my project.

I want to power the air pump with the 12V battery at the bottom, and control the flow of power/air with the PWM circuit that came from HK. I'm using the PWM for minimum power loss. My concerns are this:
To connect the power source to the circuit in a way that is sturdy and safe. I'm want to attach a female end to the circuit so I can just plug in the cable w/o cutting it up.
To connect the air pump to the circuit. I know I have to cut that cable up, but again I want to have it reliable and safe. Is there a way to make a "plug and play" connection?
To extend the pot on the circuit 2 meters. Will any similar cable size work or do I need to calculate things to get the right cable size/length/type?

I also received 3 items from a friend, after he heard of my project: A pot, a package of 2SD882 transistors, and 2 resistors. Would these components achieve a similar effect, just with greater power loss? I have a side project in mind, and with the politics with HK and the US, I don't think I can get another PWM from there any time soon.

Also also, would a good move for me be to look up colleges near me and see if any staff members w/ electronics backgrounds set up a one on one meet to help me, or do colleges in America restrict their professors to semester classes?