I'm Ava from Shopify, I'd like to help here.
I tried to visit your site just now and I'm not having a problem viewing it, it looks like the connection is secure for me!
It looks like it might be an error with the Chrome browser and some Chrome extensions. There is a guide here from Google on how to resolve these errors, this might be helpful for you! This is not an issue I seem to be having when viewing your store, but it may be helpful to run through those troubleshooting steps to make sure all customers can browse your products. Google specifies your error message too:
These steps should hopefully resolve this for you! Domains can be a little tricky to set up sometimes, but the good thing is that once it's set up correctly the first time, you shouldn't have to edit it again.
The next steps you can take to help you get some traffic to your store is to verify your domain with Google so you can submit a sitemap! This sitemap will index all the pages on your store so Google can rank your site: this is helpful when a customer does a Google search, as Google will be able to suggest your store to them. I'll include a video tutorial below to get you started if you've not gone through this process already!
I hope this helps you resolve the error message you're getting, plus will help you progress with the building of your store. Do let me know if you have any questions, happy to help!
Social Care Guru | firstname.lastname@example.org