I grew up in Texas and did not learn Spanish here. I learned Spanish while in 7th Group and continued to hone my language skills while living in South America. I also live in Puerto Rico for 5 years and learned "Puerto Rican" (yes it is different). I recently returned to Texas and I would sum up the other language spoken to "Spanglish". Spanish (IMHO) has been butchered here in TX and there are words spoken and used that you will not find in the Spanish dictionary. So my point is: Learn proper Spanish and practice proper Spanish. Speaking with Mexicans may not be the best method for a new student given the English influence and the twists ingrained into "Mexican" Spanish (Puerto Rican as well). There are plenty of Spanish speaking channels on t.v. these days such as Telemundo and Univision and a good source to practice your listening skills.
I learned and studied French first and then Portuguese. Just like the other QPs already mentioned, they all mash together. I understand Portuguese fine but it gets interesting trying to converse and not throwing in too much Spanish or even French.
Ok I could go on but will stop so as not to bore too much with a lengthy thread
Good luck to ya'll learning a new language!
Take Care