Hey there!
I would say the first step would be to shadow a veterinarian at a vet clinic to start with. That way, you'll get an idea of what the profession entails and know if that's the career path you want to pursue. Oftentimes, when we have undergrad students come shadow at the clinic I work at and I ask why they want to be a veterinarian, they answer with "because I love animals!" Veterinarians spend a lot more time dealing with people than the do with the animals. Knowing what a veterinarian does on a day to day basis is a good way to understand if that's truly want you want to do for life. You'll need a minimum about of hours shadowing/volunteering/working alongside a veterinarian and need a letter of recommendation from one when you apply to vet school.
Also, look into the high debt and mental health issues associated with this profession. Vet school is
VERY expensive and it's not uncommon for new graduates to leave with over $250,000+ in debt from school which far outweighs the ratio to their income, unfortunately.
Above all, try to keep your grades up as best as you can! I know grades aren't everything, but it's harder to fix them down the road. Looking back, I overloaded myself between working full-time and school and, as a result, did not have the GPA I wish I did which probably did not do me any favors when I applied to vet schools.
I hope this helps. I'm sure others will chime in as well with more advice for you.
