Attend coin shows
You could attend coin shows. Many shopping centers host coin shows every so often, so keep an eye out for any events at your local mall. You can often find displays of a wide range of old and rare coins at these coin shows and there is often plenty of information about them. Because competition is high, you might even find a good deal on a few coins, purchasing them for less than their normal value.
You should find new coins exhibited at these shows, and this is a good chance to make a future investment in addition to expanding your collection. Coin shows are an incredible source for buyers and enthusiasts, and a nice opportunity for hobbyists to showcase their collections. It also gives spectators a chance to see pieces of history in the form of rare coins they may never have come across before.
The Internet
Aside from shows, the internet is another vast resource, connecting you to a worldwide market full of almost any coin imaginable. A quick search will uncover countless websites designed for coin collectors, buyers, and dealers all around the world. Always make sure to research each seller first before any transactions, though, to make sure they are reliable and trustworthy. It is best to buy from sites that have been in business for a lengthy period of time and sites recommended by other coin collectors. If the website uses paypal then this is an added benefit as it is easier to reclaim your money through paypal then most other payment methods.
The internet is full of scams, but finding good or bad reviews can help guide you. Consult their terms and policies as well to see if they are willing to offer refunds should there be an issue with a purchase.
If you choose to buy old coins from Ebay make sure the dealer has a long history of dealing coins and look for any negative feedback even if it isn’t overtly stated.
Antique Shops
You may be able to find antique shops and coin dealers in your own town or in nearby areas. They are more likely to be trustworthy, since their sedentary location means they have to keep their limited customer base satisfied. These places are run by experts who can help you appraise or locate any coin you want.