A 3.47 is a very good GPA, but it depends upon which schools you are attempting to apply to. Certain schools may or may not require a higher GPA based upon the rigor of their curriculum or the prestige of the institution. A quality education can be obtained either in any accredited school, whether it be a community college, public/ private university, liberal arts school, or an Ivy League, yet what differentiates them each is perhaps monetary costs, academic standards, and the school’s reputation.
Whereas a community college, for instance, generally provides students with an Associate’s degree and greatly benefits good undergraduate students whom are simply seeking to save money before transferring to a private/ public university (or alternatively, less stellar students whom are trying to improve their grade point average), an Ivy League has upheld tradition for centuries and been renown for providing an excellent education, although with greater financial expenses.
It is not that the Ivy League is truly better than the community college, but merely that they adhere to stricter standards and provide more educational resources for the school’s alumni. Accredited state universities although vary in terms of rigor; some may well be on par with an average Ivy League and be very selective when it comes to their choice of students, yet others are more accessible to the general public and permit as low as a 2.0 GPA.
As I previously mentioned, your GPA is fine and could earn you admission to many highly-reputed schools, depending on other factors such as your SAT scores and at times, your extracurricular activities and amount of completed community service. While not all schools require that students be actively involved in the community, many upper-tier schools perceive this as an additional bonus in the admissions process. If you are as talented of an artist as you claim to be, the school you wish to apply to will also take this into account and factor it into their decision.
As for your mention of your grades holding you back from a possible neuroscience degree program, again, it depends on the school you are hoping to apply for. Some schools are very competitive in certain degree programs due to the limited number of spots available for each applicant, yet others are more flexible. You’ve stated you enjoy both art and neuroscience however, and I feel that you are possibly conflicted between either choosing what your true passion might be, or majoring in a career field that will offer you more financial security in the future. If you truly enjoy art however, you could consider all the career options that could allow you to express yourself creatively.
You could always go to a university and double major in education to become an art teacher in a school setting, or pursue a career in graphic/web design, photography, fashion design, culinary arts, or media arts/ animation at an art institute (depending on what exactly it is you want to do with art). Many of these art degrees I suggested pay well and offer more job possibilities than would, admittedly, being a freelance artist simply trying to sell their work on the streets.
It is ultimately up to you however to decide upon what you desire most for your life. Consider though that if you chose to major in neuroscience and be employed in a career you might not enjoy, you will not be happy regardless of the amount of money you may be making by contrast to the average artist. If neuroscience is your true passion in life nonetheless, then pursue an education in it and simply try to work harder to earn the grades you are seeking.