I'm not sure you're approaching this the right way.
If you want to create orders with a Payment Pending status because of your payment method, i.e. don't charge the payment method when it is used in checkout, then you should configure your custom payment method so it doesn't capture during the checkout process.
I'm no expert in this area having only worked with payment methods that are captured immediately, but I'd suggest the most important part is going to be your payment method settings, specifically the "new order status" settings.
Disclaimer: This example is for Magento 1.x, but I imagine it's similar in Magento 2.
In Magento admin, under System -> Configuration -> Sales -> Payment Methods -> Your Custom Payment Method, there will be an option to choose "New Order Status". For payment methods that aren't captured immediately this should be "Pending". This will mean that an invoice is created, but the payment method is not charged immediately: