Please if one sees goods/products on internet to buy, how can it be delivered in Nigeria. e.g from stores in London, USA. Thanks

You can use a credit, debit or prepaid card that will be accepted by foreign (UK or USA) seller and use a foreign (UK or USA) shipping address in case such seller does not ship outside the UK or USA. Alternatively, engage the services of those that can buy and forward the items to you in Nigeria.