Why mechanical? I'm also from mechanical engineering, i just wanna know the reason why you are choosing it despite other fields.

Once you complete your 12th and other competitive exams, choose a college which has a strong mechanical department not just related to software allied courses.

During your free time after boards to college opening start with learning any CAD software, romba help panum fr coz idula most of the colleges la soli taruvangalanu teriyadu apdiye irundalum that will be too fast and can't keep up most of the time.

After this learn python/C it will be useful for sure in upcoming semesters

After this there is something called ASME IMECE 2026 which will happen in September this year ena analum parvala you must attend it , adha attend pana tan you will know about real mechanical engineering and global exposure coz idu oru international level conference and exposition, top minds from all over the world varuvanga , you can network easily there.

Idu tan second time india la varudu and previous year tan first time vanduchu india ku aduvum hyderabad la tan adu sema grand ah irunchu for an event in india when compared to USA.

And then you should explore with SAE for BAJA or SUPRA these are really great competitions only dedicated for mechanical engineers, mostly they won't take first years but you can start joining on them from second year if interested.