Studying eng or CS may be a help for snagging AFROTC, but get the application in as early as possible. Also check Army or Navy if interested. DD did a year of AFROTC in college as a sophomore but got cut before field training (summer between sophomore and junior year) - the calendar year they had big budget cuts (if she was ready for field training the year before, she would have been fine as 99% of her major got in and she had excellent recommendations from her local command).
If you do get ROTC at one school, do not think you can change schools and move the ROTC scholarship $$ either.
I know a retired AF Col who was in computers (went through UG with ROTC) and there were sweeping years where if you were in the wrong year they may not have had you stay in even when you wanted to on re-enlistment…Col hung in and advanced but would have advanced sooner on other year in.
I know a student whose older siblings received 4 year ROTC money, while he began as a FR in ROTC but only had the 3 year scholarship. All military branches have had such a big fall out over the FR scholarship students.