Hi there- you're asking two questions here. One, you're asking which tool is better for blogging. Without a doubt, WordPress is the better tool. Then you mention selling services, where Shopify would typically be a better choice.

Based on only what you've shared here, I recommend WordPress + WooCommerce and avoid Shopify altogether.

I'm happy to discuss this further and help navigate getting your website started. Book a call or send me a message.

All the best,
-Shaun