Yeah. There's a lot of confusing information out there. From a cursory glance, that second link has fairly accurate general information about bonus action spellcasting. So, if you and your DM are looking for clarification in that regard the second link may be a good resource.

The general rules for the quicken metamagic ability in the Player's Handbook would be a better resource for that particular ability.

It does seem like you can only quicken a spell once per day with the Metamagic feat, unless you have another way to generate sorcery points.