Seriously frustrated wanna be gamer

First thing first did you buy xbox live or was you using free trails.... you can't play online until you buy live even if the game is free... but more details about the error will help us

I could be misunderstanding your complaint. It does sound like your free 2 week trial of Xbox Live Gold that came with your Xbox expired. At this point you will need to subscribe to continue playing. Talk to your parents. Best wishes.

you can check the status of your Xbox Live Gold at https://account.microsoft.com/services/. just sign in with your Xbox account.

as others have said, your Live Gold probably expired when your Xbox was in for repair so there isn't much that can be done except renewing your subscription but there are ways of getting Live Gold cheaper or even free.

check the store for offers as there are often offers for up to 3 months of Gold or Game Pass ultimate at very reduced rates. (Game Pass Ultimate includes Live Gold but also gives you access to the Game Pass library of games. check this link for details and
talk to your parents about it
https://www.xbox.com/en-US/live/gold/upgrade)

you can also sign up for Microsoft Rewards which gives you points for using Bing search engine and Edge browser as well as doing daily tasks at

https://account.microsoft.com/rewards/. it will take a while to earn enough for Live Gold but once you get there it is easy to keep your Gold up to date using MS Reward Points.

if you do get Game Pass Ultimate you can earn more reward points by doing Game Pass Quests on your Xbox by playing Game Pass games and earning achievements.

you can install the Rewards app from the Xbox Store on your Xbox.

I'm sorry this isn't a quick fix but hopefully it will help in the long term.

You can go to a place like Walmart or gamestop and purchase prepaid codes for either 1, 3 or 12 months of live since your trial has run out.

As everyone seems to be hinting at, double check the fine print on the card for that code to see whether or not it was a full subscription code or if it was indeed a trial code. Should it not have been a trial code, there may or may not be something wrong
with your account/console... which is highly unlikely. Have a parent (or with a parent's permission) contact customer support if your investigation of that card that came with your console does yield something suspicious/not right. https://beta.support.xbox.com/contact-us

When contact support, remember to be clear and concise about what you're asking for help with so they can help you to the best of their abilities.

Also, people on PlayStation have similar issues almost as frequently as people in the Xbox community do. Its nothing to write home about and be upset over, you just gotta have patience my friend.