Traditionally, conductors of choirs will not conduct using a baton unless they are leading a full orchestra along with their choir, whereas conductors of orchestras and other large ensembles will use a baton.
Using a baton is an additional skill; in programs of conducting pedagogy I've seen, all students will work with a baton in their first few semesters "just in case" before breaking into separate groups for instrumental vs. choral conducting later on (with the choral folks not using a baton at that point).
Of course, there is no hard and fast rule for this; notable badass Pierre Boulez is known for never using a baton at all, and I know many choral conductors who simply prefer to use a baton. At the end of the day, the technique of conducting is all about providing nonverbal communication with a maximum of efficiency, and in order to do that you need to know both how you can best operate to provide effective musical leadership, and what your ensemble is going to expect based on their experience with you and other conductors.
Now, the "tradition" I mentioned does exist for logical reasons, and these may inform your decision:
- Choral music is typically more homophonic than instrumental music; the tip of a baton offers a higher "resolution" for the point in time than a human hand, and so is helpful in polyphonic (rhythmically active, in particular) instrumental music. Likewise, some orchestral conductors will opt to lose the baton for a slow and homophonic piece of string orchestra music that will have a "choral" texture.
- A typical choir is on average closer to the conductor than the more spread-out musicians in an orchestra; a baton makes your movement easier to see from a distance
- The shape of the hand is a variable that can be "implemented" to communicate with your ensemble -- vowel shapes come to mind. Using a baton puts you at -1 hand.
I'm of the opinion that you don't necessarily have to lose anything by using a baton provided you are sufficiently skilled with it, but that the benefit for most choral conductors in using a baton is far outweighed by the effort required to gain that skill. As such, most choral conductors I know don't use a baton unless they feel other factors require it. Personally, I have conducted both kinds of ensembles, and tend to stick with the traditional lines for the reasons described above and so the ensemble is more comfortable (particularly important for young students).
For your purposes, I would suggest going with what you're comfortable with and using your hands. Even if you've never conducted before, I wouldn't suggest getting in front of an ensemble with a baton unless you've had some training and practice with it.