Own Intergrated Crypto to Purchase Other Crypto

Trying to follow some professional advice and I like the idea .

If i have my own crypto and my own payment engine i can accept payments from people and give them my crypto to spend in my market to buy other currency .

I see where it says peatio can accept payment gateways apis so that is good but im not there yet .

How or where should i start to add the crypto i made as a default currency for the exchange .

And if i do this , would my coin be the correct value to trade with others?

How would i even start