I don't spend a lot of time wondering about it at this stage in my life. I suppose when I was in the "pondering-all-of-life stage" (late teens, early twenties) I had to form some kind of "opinion", and this is the opinion I came to:
Either there is an afterlife or there isn't. If there isn't, then it's really important that we make the most of the life we have on Earth. There's a lot of good we can do while here on Earth, and that can be our legacy. There's a lot of beauty in life, and we should enjoy and appreciate the gift of being able to experience that.
If there is an afterlife, we'll discover it when the time comes. It would seem to make sense to me that if there's "something else" then there's some reason we're here first and then there. Again, spending our time, energies, thoughts, and efforts on life on Earth would seem to make sense. Life is short. I'd think we're supposed to focus on either stage (this one or a later one) when we're in it.
As far as reincarnation goes, I don't believe in it. I believe that each newborn human being comes into this world with a brand new little soul and a "clean slate". That's kind of how life seems to work. The trees don't get recycled leaves each Spring. They get brand new ones. Each wave that forms in the ocean is new, heads toward the shore and breaks. Other new ones are formed. I just don't think Nature would recycle something as fundamental as a soul.