I want to pursue a career as an Dentist. Before that, I am planning to major in Biology in my undergrad studies. What are some great opportunities out there?

If you feel strongly about a career in dentistry, then I'd seek employment or volunteer opportunities in dentistry. If you intend to be a clinician (as opposed to, say, a researcher or academic), then there is no substitute for working in a clinical environment.
This practically means a dental office or clinic. You don't say from where you're writing. My first-hand experience is totally in the U.S., and there may well be many significant differences between general dental practices here and abroad.
The closer you can get to the dentistry the more you'll learn. As a chairside assistant you'll get to know the instruments, techniques and materials. You will have a huge step up on most other applicants.
Try not to accept a volunteer position in a private practice--at least not more than a week or two. Many potential employers will exploit free or cheap labor if they can. Volunteering in the clinic of a voluntary (non-profit) hospital with a dental department may be another route.
The atmosphere in dental offices varies wildly. You should be given opportunities to learn. Like anything else, there are good and bad positions out there, and here I'd go with my gut.
If you have a family dentist that you like, that is a great place to start. If he/she doesn't have a position they may be able to point you in the right direction. You can also get information calling the local dental society.
There are several specialties in dentistry (periodontia, endodontia, orthodontia, pediatric dentistry and others) that you may find interesting, but IMO it's best to get a good overview of general dentistry before you even think about specializing.
And once you've had the opportunity to work in a few clinical settings and dentistry is losing its appeal (assuming you weren't just surrounded by a bunch of losers), well--it's still better to find out now and not after you've spent 4 or 5 years and accumulated a huge financial debt.
Good luck!

Hello Rohan,

A practical way to decide between a career and another is to list the main activities of both professions and see which tasks are (in the careers in question, in this case, biology and dental medicine) that you appreciate most.

Another way is to perform voluntary activities in both professions, and find what is the work environment that you most identified, because is not enough to enjoy a career, you must see if you present the skills needed to practice it in the daily routine.

Basically, that's it. I hope I have help you to reflect on your choice.

Very lucky!