What are my chances as an external transfer?

I’m a freshman engineering major at A&M. I’d really like to transfer to biomedical engineering at UT or maybe to biology at UT. My current stats are a 4.0 college gpa and membership in the society of biomedical engineers at A&M. I’m also planning to join an undergraduate research lab and join an engineering design challenge. Are there other things that they look at that could help me? I have to submit them, but do they actually look at high school stats for a transfer like this? My current plan is to go BME into premed, would it be smarter to do biology? I also saw somewhere that said you’re very unlikely to be able to transfer into your second choice major, so would it not even help me to apply to transfer to BME with biology as a second choice? Sorry for the block of text I’m kinda nervous about this whole process.