Marriott has 3 elite statuses:

Stay 10 nights for Silver. Not much to this, just 20% extra points

Stay 50 nights for Gold. This is a big step up from silver but gets big rewards at FS brands (Marriott/JW/Renaissance/Autograph) including guaranteed free wifi, breakfast and lounge access. Room upgrades too, subject to availability, don't expect suites though!

Stay 75 nights for Platinum which really simply adds extra points.

You need to be Gold but the only way to get there besides staying the nights is with a credit card and only the v. Expensive Ritz Carlton credit card gives Marriott Gold. Not available outside USA, alas.

As others have pointed out, ringing Marriott for a status challenge may get you upgraded. There are 2 offers:

1. Road to Gold. Stay 6 times in 2/3 months for Gold. Status only kicks in when you complete the stays.

2. Taste of Gold. Immediate status upgrade to Gold for 2 or 3 months which to keep for the rest of the year must complete 6 stays.

The taste of gold used to be uniformally offered to anyone who asked. Now it's much tougher. Your best chance to get offered the taste is to have a screenshot showing lots of stays with a competitor, or to reserve lots of stays on Marriott and then call asking for the taste on the basis of the multitude of stays you already have booked. Neither are guaranteed to work. You're far more likely to be offered the Road to Gold