There are Counterwallet (how-to) videos on YouTube and you can also find step-by-step tutorials such as here: https://github.com/CounterpartyXCP/Documentation/blob/master/Tutorials/User_Tutorials/tutorials.md (Create a Token is the one you are probably interested in). The first tutorial (Getting Started) guides you through the wallet setup process.
Once you have a wallet, make sure you write down (not save on computer) your pass phrase because you’re the only person who has a copy - there’s no “recovery” procedure!) and then send some BTC (e.g. 0.01) to the address in the wallet.
To register a coin you need Counterparty tokens (0.5 at least) and you can buy them on exchanges such as Poloniex or through service such as Shapeshift (to which you’d send just enough BTC from the wallet address to get 0.5 XCP in return). Then you can follow Create a Token/Coin tutorial.
Tokens can be sold on the Decentralized Exchange and also (more friendly) via vending services such as Tokenly and CoinDaddy.io (these sites have good help and video tutorials as well)…