Protect your Rockstar Social Club Account with Double Authentication and Rockstar will net you 10 Free Gold Bars. You can do that on their social club website through your browser in security settings.

2-Step Verification Rewards are always the same, they include 10 Gold Bars, it may take some time to receive them.



Link your account to Amazon Prime. If you don't have it start a trial (or another trial) but don't forget to cancel it before you are billed. Get your rewards, very often a free role like right now. That is 15-25 gold bars saved (earned and invested).
I suggest starting a trial only when the rewards are worth it, like free role because this is one time only thing. Rewards arrive within 3 days but if they don't you can ask Rockstar support to reimburse you. Then you will probably get the role gold in gold bars and will be able to spend it on another role of your choice if you wish so. Eventually, like months or weeks after that, you may get your initial reward as well. So it would be double profit. DO NOT LIE to Rockstar support. They can check and you'll be in trouble. Only contact them once the time has run out (after 3 days have passed) I suggest live chat
https://gaming.amazon.com/loot/reddeadonline

If you are starting out a good way to get Gold is to do stranger missions. The longer you complete them the more gold you get. Best results are gotten by playing a mission for 30 minutes from its start. Countdown starts from the start of the mission and not the timer.

Play showdowns, Online PvP mode that lets you earn gold. Accessed via ESC main menu or L player menu quick join enable double security with email or phone for 10 gold bars

Do at least 1 daily challenge for 2 weeks and then really unload and try to complete as many as you can week 3-4

Open treasure maps, you can get them as random loot, from trees (rare) and every 5 levels they are sent to your storage.

If you have bounty hunter, then do legendaries and spend half an hour on them then you get nearly 0.5 gold bars too. The higher the difficulty the more you get.

Free Roam events give gold too

And finally, RESET AWARDS in game for 0.4 gold bars. Awards are in ESC > Progress > Awards. Sometimes they bug out and cannot be reset. If you get an award it will show up as a tip during gameplay so you can just hold F1 to get to it without going through menus. Then you can reset it and then hold ESC to return to game.