It is possible to buy e-currencies both on the official website of the bank payment bills and from many exchanges.
It is more convenient to buy cryptocurrencies on cryptocurrency exchanges. Simply sign up for any popular one. The list of the exchanges can be seen here.
Through these services you can exchange electronic money for a transfer to your bank account or a credit card.
It is not worth exchanging e-currencies in the forums which offer good deals. Such exchanges often end in a scam.
Conclusions: There are more those wishing to cheat you on the Internet than the money you have.