@EmilyBui Yes, your SAT will matter no matter where you attend, even if you are in the top 10% of your graduating class. A low score won’t hurt you getting in, as by law, being in the top 10%, you have to be admitted but it could hurt you getting your major if you do not take it seriously.  Also, there are some caveats to being top 10%. To qualify for the top 10%, you must graduate under the recommended or distinguished plan.
You need to go ahead and apply to all of the schools you are thinking of attending right now, not after the scores come out. Go ahead and do the applications and get them sent in. If you are not ready to upload the essays at the same moment, you can upload them later and submit them. Know that you can only submit them one time. Read this about submitting essays. https://www.applytexas.org/adappc/html/faq_essay.html
When you take the SAT in Oct, sign up to send the scores to every college you have applied to and those you may still apply to before Dec. 1. Scores are sent for free if you request them at time of taking the SAT and will be received before they actually show up in your College Board portal.  Otherwise, you will have to pay to have your scores sent, per university, from College Board. I would have to go back and look for certain but I believe it is $15 per university. That could get expensive.
Where you do your pre-nursing may not be where you get into a nursing school. When you are ready to apply to nursing school, you will want to apply to more than one, because you may not get in to the one where you are attending for pre-nursing.
TAMU Deadline to apply is Dec. 1
UTSA is March 1, 2018
Texas State March 1, 2018
U of H is (Nov 15. scholarship deadline) June 30, 2018
The most cost effective is if you have a university with a nursing school close to or in your hometown, live at home and commute. Meal plans and boarding are sometimes more than the actual cost of tuition. Fees at some universities are high. You need to look at what it costs to attend everywhere you want to go.
You need to file your FAFSA. It opens Oct. 1. You will need to have your parent(s) tax returns for financial information. Read this to educate yourself on what you need to do where. http://www.collegeforalltexans.com/index.cfm?objectid=63188B97-0C47-0020-6DBBBAD96A7DFB83
Search the school’s you apply to websites for scholarships through the university you can apply for. Check your counseling office at school for a list of local/city/community scholarships you can apply for (usually availble in the spring). All of these can help offset the cost of college.