Making gold chloride isn't a home project (at least for normal people). At the least, it will require making aqua regia -- combining two hazardous acids (concentrated nitric and concentrated hydrochloric) -- in order to react with gold (because neither nitric acid nor hydrochloric acid will react with gold at a useful rate, even if heated, but aqua regia will). You'll also need to have "fine" gold, purer than even 24k -- for which you'll probably have to pay bullion price (and a premium to get it in gram quantities -- last I saw, gold was headed for $4000 per Troy ounce, which is around $130+ per gram, plus the premium for handling and packaging those tiny gram-range flakes).
Once you have the gold dissolved in the aqua regia, you have to ensure that it precipitates as the chloride, not the nitrate (I'm not a chemist, so I don't know if that's a problem or not), and dispose of leftover acid.
I expect Nile Red or Cody's Lab on YouTube likely has a video about this process (Cody or a close relative owns a closed-down gold mine and Cody has a slightly impaired sense of self-preservation, and Nile Red is a real chemist); might be worth searching and viewing before making the decision to attempt to get the chemicals to make your own gold chloride.