I'm Miles from the Social Care team at Shopify. Sorry to hear you're not able to pay for the plan. If your card is declining, there may be a couple of reasons for that. I'll go through the possible Shopify related reasons, but if these don't fix the issue, my suggestion would be to contact your bank for further help.
At Shopify, we only accept payments via credit card. The only exception to this is businesses outside of the US are able to use PayPal for their payment method. Are you using a credit card to make your payment? If you're using a debit card, this is the likely reason the card is declining. If you're outside of the US, you are able to use your debit card via PayPal instead. You can learn more about Shopify's payment method here: https://bit.ly/2H3P4ks.
Another thing to look out for is to make sure your bank accepts international payments. Shopify charges your plan in USD, so if you're banking outside of the US with a different currency, your bank may be declining the transaction. If this is the case, contact your bank and ask them if they allow international transactions to make sure you can pay for your invoice.
Once you're all paid up, you'll be able to access your store. What stage are you at with building out your website? I recommend checking out Shopify Compass. Shopify Compass is great for beginners, as well as experienced entrepreneurs, as it provides you with webinars and courses on things like store design, marketing and more. It's 100% free for everyone and new content is being added all the time. This program will help you drive more traffic into your store and also convert that traffic into sales.
If you're new to marketing, I recommend checking out the Shopify Blog? It's got loads of great content on ways for you to drive sales into your store. I've got some great recommendations below that I'd recommend taking a look at:
Driving Traffic but No Sales?
* We give you 13 steps to improve your conversions.
* Who is your target audience, and does your sites look and feel cater to them?
* Is your business trustworthy? (Also see the next recommendation below for more on this)
The 39-Point Store Trust Checklist
* Work through a checklist to make sure your store is trusted by potential customers.
* Look at the "nice to haves" vs "must-haves" in your store.
* Do you have essential information for your customers to view, like policies?