Question about shopify

Hello, first of all, I want to apologize if this isn't in the right section, my question is as follow, I'm working on a shopify store but I'm not a web designer and I'm doing it all by myself, i want to know if there's a CMS or way to code my template files without having to create a shopify account and use the 7 days trial (since I'm not a web designer, sometimes it takes me a bit longer that it should some simple fixes or changes), something like the Wordpress CMS or i don't know, thank you all and again, I'm sorry if this isn't in the right section or if this a dumb question.

Use shopify developer account

Does it have a expiration date?

You can message the Shopify support team. Sometimes they will extend your trial by one or two weeks

I think trial is 14 days. After that you can contact Shopify and ask for week or two more. They will accept you

Shopify's advantage (against WooCommerce) is their support they will surely help you!