I have read articles and watched videos but they don't seem to explain how it works to me, please I really need help
It's technically complicated as you might expect. Firstly, you need to know basic software development (not just web development). You need to learn how cryptocurrencies work (ie. decentralized mechanisms and consensus protocols).
Then, you might then want to search github for the cryptocurrency wallets source code for a crash course on how it works. Read the code and understand the code.
Again it's not as simple as it seems. It's way more technical. But once you get over the learning curve, it will be easy (conceptually) to develop.