Would a half marathon be doable in October with little outside running experience?

It’s about 23 weeks from now. I am 25F.

Currently I don’t really run outside, mostly indoors on the treadmill. Over the past 8 months I’ve run 2 miles 2-3x a week. Mostly interval training though, not too much distance work. This is mostly for cardio and not training for anything specific. The most I’ve ever run indoors on the treadmill is 3.5 miles in one go.

I don’t really care about time, I just want to finish it safely.

If I did increase my mileage and started running outdoors, would it be possible to train for it starting now? And would running on a track be suitable? I don’t run outside normally because of safety reasons, and the town I live in is small and there aren’t really long distances to run.