Hey,

Astrochemists are the ones who study periodic table in the context of space. Astrochemists examine and analyze the space objects at molecular levels. For Astrochemistry, you need to have a strong background in chemistry and good logical thinking. For this it is preferable to choose your graduate courses which focus more on chemistry, Astrophysics etc.

Astrobiologists are the ones who study the origin of life in the Universe. For this you always need to start from the basic which is taking science in 10+2 and graduation level.

After having a graduation degree. You can go ahead and apply for higher studies in Astrochemist and AstroBiologist in abroad in you desired country.

Hope this helps. Thank you.