To build an online website, considering an eCommerce CMS is a wise choice. Especially if you’re already familiar with WordPress, this platform will help. It supports a wide range of free payment gateway plugins. Login to the admin panel, search for the right plugin and get it installed with ease. You can hire a programmer if your website is using Core PHP or a PHP framework like Codeigniter or Laravel. You can try a freelancer website to find someone with knowledge and expertise in the field. I hope the above is useful to you. Please let me know if you have any questions.