Depending on your current status, you can earn several tens of thousands of point - https://www.marriott.com/loyalty/ear...ding-events.mi

Just make sure your Marriott # is on the contract and the points will automatically show up once the final bill is paid.

Using a co-branded card is a good idea. You folks in the US have many to choose from; I'm sure you'll find something appropriate. Since you currently have no Marriott status, I'd recommend you get a card first that grants you some level of status as this can greatly affect the number pf points you earn via Marriott Meetings.