Girlfriends for betta in new tank?

I think generally unless you are planning on breeding and know when to introduce/remove the female, it's discouraged. But I could be wrong.

Do not get females. He will kill them or maybe (since they are just as agressive as males) one may kill him. Contrary to popular belief females cannot be kept together unless you have a very large tank. This also goes with males.

Actually Tonalea, you are completely correct.
Even the most docile combination of male/female bettas, with the exact correct stocking arrangements, and lots and lots of plants/hiding places, the females will die off one by one, until the male dies first. And if you are left with two females the smaller one will die. And then there will only be one left. Trust me on this one, do not do it. Even if the LFS people say that you can, and even if your tank is big, they WILL find each other. And when they find each other it is not pretty.
There are reports of people having successful male/female betta tanks, with just the right numbers (4+ females) to avoid bullying, in huge tanks. Initially there are no signs of aggression for 1 month or more, even. And then they kill each other. Out of the blue. For no reason at all.
So you will be spared a lot of heartbreak, trouble, worries, money and pain if you stick with 1 male.

no, females CAN be put togther just females only tho. in a 10 gallon u can have 4 females maybe 5 dunno let the experts pin this

Females can be kept together but they need to be in larger numbers to spread out aggression. Sometimes females don't even get along with each other. Bettas are all individuals.