We'll have to see if the major exchanges carry Bitcoin Gold once it is released but the way to get Bitcoin Gold is to hold as much BTC as possible on the date of the hard fork. Keep holding it until August 1st then you will be able cash out your newly minted altcoin.
It's impossible to confirm because the Bitcoin Gold website has been stripped bare, but I'm reading on Twitter that the hard fork has already occurred. Right now, supposedly, the developers are pre-mining the forked chain and are going to "launch" it on October 25th, not fork it on that date.
There really isn't much information available. Their Twitter says that October 25th is still the launch date, so I suspect it's true. Originally, they were planning to do a pre-mine and then offer the pre-mine as an ICO. Now it seems like they are just pre-mining themselves.
If they are in fact doing that then that coin is going to crash even faster and the ones forking bitcoin are going to lose all credibility in crypto, so let us hope that is an unfounded rumor, because even if I do not believe in any of the forks at least I want to think they are being honest about their desire to change bitcoin and that all of this is not just because of money.