I didn't want to have 5 different names. Now that I am living here I would like to have a much shorter name being my first and his last.
As this is a complete change (eliminating part of the name, shortening the last name, and adding a new last name), it's not a simple procedure as changing at the time your marriage license was procured.
Does anybody know where I can begin to do this process? Who do I contact or where do I go?
First, you'll need to have your fingerprints taken (search online for locations near you), then submit it to TX Department of Public Safety and the FBI to get a fingerprint card (insignificant fee.)
Then you'll need to fill out Original Petition for Change of Name of an Adult, and Order Granting Change of Name of an Adult (forms are available at county court), have both forms notarised, then submit the originals, 3 copies, fingerprinting card, and your photo ID to the courthouse. The filing fee is high in TX, between $250 - $350. You'll receive a hearing date when the judge can hear (read) your petition.
At the hearing date, the judge will ask the reason you want your name change. After s/he signs the Order Granting Change of Name, you'll file it with the court clerk so s/he can stamp it. Make sure to pay for a few certified copies because you'll need them.
Can I just start using my new name and get an ID and not have any problems here?
No, you cannot. Yes, you'll encounter a lot of problems .
You must notify Social Security Administration of the change and request a new card with new last name (free) using one of the certified copies. Until SSA recognises your new name, no agency in the entire country will.
Will I have to change my Green Card, passport, resident card, birth and marriage certificate?
With the new SS card, you'll submit a request for new DL from TX DMV (insignificant fee).
The name on your passport MUST match the name on your DL, green card (I don't know the cost), and resident card (don't know the fee on this either), else you cannot pass through Homeland Security when you travel, so you'll need a new passport ($110).
You cannot change the name on your marriage license because that was your legal name at the time of your wedding and that's how it was registered with the court.
Do I have to notify brazil? Will I have any problems if I one day want to visit Brazil?
That, I don't know.