There are lots of ways to create your own crypto coins.
You can make one from scratch using blockchain technology .
OR
You can make one on an existing platform (Ethereum/Waves/etc…)
I do see a lot of people use WAVES these days to create a token, here is a rather useful link for that platform - wavesplatform.com
I also recommend google. there is a lot of info out there.
There is also much quicker and simpler solution.
Download the Waves Wallet
Click on the Token Creation tab
Give your token a name, how many you would like to create and if you want it to be re-issuable (re-issuable means you can create more in the future / not a fixed amount)
Hit Submit
Boom. You now have your own crypto coin which is immediately tradable on the in-built Waves Decentralized Exchange (DEX) or it can be listed on any other exchange.
Note: It takes 10 seconds to process the request and costs 1 Wave to create coin.