What any new eBay user generally should do before bidding or buying, or anything at all, is first establish a payment method that works for international orders, and most importantly, make sure they can actually afford whatever they are bidding on or buying, while putting currency conversion and fees into consideration in the process.
Usually a central bank in any nation should be able to perform international transactions after a verification of transaction legitimacy procedure (otherwise known as a banking account safety and security feature), usually via phone call or an in-person bank visit to unblock the 'strange new transaction' on the account;
There's also checking to see if one can utilize PayPal as a payment processor, which is usually a good indicator on whether you can pay for items online internationally; however, support may vary on a country basis, and Paypal apparently is being phased out from eBay or something.
For countries that either have certain difficulties (currency exchange rates, remote locations, unestablished courier or logistics networks, etc.) or are not supported, usually the best option is to utilize the assistance of either a relative or a trustworthy friend living in a supported country; there's also the option to find an online service that can act as a middleman both for payments and receiving the item, which will in turn ship it to you; however these will be paid/subscription services, and will cost one extra.
