While you can use metamask and the bsc extension for desktop/browser.
Binance Smart Chain isn't much different from the Ethereum network as you will discover soon so the option of using Metamask is also fine. I have used it and it worked flawlessly. However, you need to add the Binance Smart Chain network settings on the wallet before you start using it. There should be a guide for this though I haven't been successful in locating it right now.
Ya, I am using Metamask, it looks better than the rest, not installing too many wallets will make it easier for me to manage. But does it only work as a browser extenstion? What about mobile wallets? Can I connect?
Should I only connect to the mainnet? The tutorial mentions adding both mainnet and testnet
There is no "beta".
BSC is pretty much an exact copy of ETH (but PoA plus some changes). All you have to do is change the RPC server you are using on the MetaMask. Think of that like you're changing your Electrum server to one that uses a Bitcoin ForkX network so you can spend on the forked chain.
LoL, it seems that my source of information is not correct
Got the instructions from logfiles and I think I can try it now