Go to uscis.gov and download the Guide for New Immigrants. https://www.uscis.gov/sites/default/files/document/guides/M-618.pdf
Do explain - if you just received your green card that means you've entered in the US, were processed by immigration at POE and have paid for your green card if you've received it to the listed address (Texas).
You can change the address online on uscis.gov - you actually HAVE TO notify uscis of your new address within 10 days of moving.
Depending on which state you live in - google drivers license STATE
Credit score you get by opening bank account, credit card, utilities, getting a mortgage or another form of debt - car loan for example. Getting a job can help with all that.