Create a better payment flow for my website

I have a website that requires to have the payment linked to the registration section.
Currently, they have to register and then come back to pay which doesnt work well.
I would like them to complete the registration form which will then lead them to the payment page (which is linked to my PayPal account) before they have their place confirmed.

I do not envisage this to be a lot of work and so I have priced the job on the lower end.

Thanks