Update>>> I have the 12 word phrase and the 34 letter and number address for wallet... Mom passed away the day after Thanksgiving. I have all her paperwork and mine as I was her only child. I have a string of numbers and letters and a 12 word collection related to her bitcoin however I am not at all familiar with bitcoin and am not very versed in technology. How should I proceed? Thank You.
I'm sorry to hear of your loss. Recovering the funds will require some careful work, but go slowly and make sure you understand what you're doing, and you'll find it isn't that hard!
Importantly: Be very wary going forward - lots of scammers will likely attempt to prey upon you and steal your funds! DO NOT share the 12 words or 34 letter string with anybody online! DO NOT input those words into any online website or service. You do not need to trust or depend on anyone else to recover the funds. There is no 'official' anything in Bitcoin - it is a decentralized network without any admin. You (the user) are in full control, you can accomplish all the required actions without any dependance on a third party (except for the sale of BTC -> fiat currency, perhaps).
Those words are the 'key' that will allow you to spend the bitcoin, so to speak. To use the key, you will need to find some secure wallet software. I would suggest starting by looking at bitcoin.org, and selecting a wallet from the list they have there.
Once you have some wallet software running, you will want to select an option to 'recover'/'import'/etc your wallet, at which time you will be prompted to enter the 12-word mnemonic seed phrase. Once you do so, you should hopefully see the wallet load properly, showing the funds and all past transactions.
If an empty wallet with no transaction history loads, then you will likely need to select a different 'derivation path' for the wallet to follow. Some wallets (eg Electrum) allow the user to define a derivation path, while others do not. You may need to find software that allows you this more fine-grained contro.(Under the hood, the wallet is using the 12-word phrase to derive the cryptographic keys that allow you to spend the wallet's funds. There are different standards for which keys the wallet will derive, selecting the correct path is important!). It is helpful to know which wallet software was originally used to create the wallet, but if you don't have that information then all hope is not lost, it might just take some extra work. You could take a look at WalletsRecovery.org for some help/info.
With the wallet recovered, you will need to find somewhere to sell the coins for your local currency. Do your research to find a reputable service in your area, as you'll need to trust them completely with your funds. Once you've made a choice, send a transaction by copying the deposit address from the exchange service to your wallet's 'send' field. You can then make the trade for your local currency, and withdraw to your bank account by whatever methods the exchange service offers.
Keep in mind that you will want to make sure the device you load the wallet onto is secure. For example, a brand new iphone is going to be a more secure device than a 10-year old windows PC that hasn't been updated regularly.
You may want to consider how much BTC is at play here - if it is a huge sum then it may be worth first acquiring a small amount of BTC yourself first, to familiarize yourself with the tools and procedure of sending/receiving/recovering funds. That way, if you make any mistakes, you will just lose a small amount of funds, instead of the inheritance.