Xbox One 1 Month Gold Trial

No first you cannot use the 14 day trial with a 1 month

It's either use the 1 month first

seeing as you are gold either you are on the one month trial

You cannot use the 14 day trial while gold you must be silver

The free month of Xbox Live gold can be applied from the account creation process if you are making a new account.

Or

If you already have a Microsoft account and don’t have an active Xbox Live Gold paid subscription, you may be able to sign up for an Xbox Live Gold one-month free trial subscription.

Here’s how to sign up:

1. Sign in to the Subscriptions page with your Microsoft account.
2. If you’re eligible for a free trial, you’ll see Gold – 1 Month FREE Trial as a subscription offering. Select Gold – 1 Month FREE Trial, and then select Next.
3. If prompted, add a payment option to your account. If you already have a payment option on file, you can use that.

Important At the end of the first (free) month, your trial subscription automatically turns into a paid Xbox Live Gold subscription that renews monthly by default. The paid Xbox Live Gold subscription will renew to the payment option you
added to your account.

If you don’t want the Xbox Live Gold one-month free trial subscription to renew, you must cancel it. See “How to cancel an Xbox Live Gold trial subscription,” below.

For more info go
HERE.

I should be able to do everything a normal Gold member could.

The one month trial that require a credit are eligible for the games with gold.

Source:
support.xbox.com/.../games-with-gold-faq

I'm pretty sure the 1 month trials is the same as paid ones, when using your credit card info. Only the 14day trial and the 2day trials are not.

The 1 month trial gold that comes with the console doesn't gives you access to all features. For example you can't join multiplayer games with the 1 month trial gold.

Was the code for a full gold subscription (1 month, 3 month, or 12 months)? Or was it a gold trial? Trial cards will allow you to play online, but won't change your account to gold.