If you have a two channel amp and only use 1 channel for now, would all of the amps power from both channels go through that one channel being used or would it stay the same as what it is supposed to put out per channel?

This can only happen if the amp allows the capability and then you actually wire it like that... - Bridged.

Each of the 2 channels supply half the capable output of the amp ever.

Only bridging the connection would force both channels(stereo) to join as one master channel(mono).

Look at the speaker terminals itself. If there is a bridging diagram on it, then you know for sure it's safe.

If there isn't, look in the manual.

This.

I'll only add one thing. If you can bridge it, check to see what the minimum stable ohm load is.

Not sure what you are trying to run.

If you have a two channel amp and only use 1 channel for now, would all of the amps power from both channels go through that one channel being used or would it stay the same as what it is supposed to put out per channel?

If you literally only use one of the 2-channels then no, all of the power will not go through that one channel. Power output may go up just a smidge (a measurable but otherwise meaningless amount) compared to utilizing both channels as the power supply would be under less stress and such, but otherwise no realistic and no audible difference in output would result from only using 1 channel. The amplifier would still be restricted by the rail voltage and current capabilities of that particular channel as far as output is concerned.

However if you are talking about bridging then the power output would be that which the amplifier is rated to provide when bridged.

More information about what exactly it is you are doing would be helpful.

Don't leave 1 channel unhooked, amps don't like running with no load.