No, really, I'm serious.

I have lots of female friends and I have learned so much from them about how women think and feel, including how they relate to men and relationships. The knowledge you will get from talking to your female friends about what they like and dislike, how they see the world, what they're attracted to, etc., is absolutely invaluable. Here a few more concrete benefits to having female friends:

1. They can introduce you to their female friends/acquaintances. This, by itself, is invaluable. I've gotten a handful of dates this way.
2. If you have some girls in your group, women you don't know are more likely to trust you because you've been "vetted" by another woman as safe and trustworthy. This is a HUGE thing in a woman's mind when she's looking for dates or even just hookups.

This next bit is more subjective, and relates more so to how I live my life, so this might not be the way you want to do things but I personally think it's a good way to live.

Being in the mindset of seeing women not just as romantic or sexual opportunities but also as potential friends will, ironically, enrich your dating game greatly. When I "cold approach" girls I meet, I'm not going into the conversation with the mindset that this girl is only good for dating or sex. I expect more or less nothing from the conversation, and I am perfectly happy with just making a new friend. Friends are awesome, and we're too bloody isolated in this society. The more friends you have, the richer your life will be in general, and if your friends are women, all the better for the reasons mentioned above. But here's the thing:

If you're talking to a girl with the mindset of being ok with just being friends, you will pressure yourself less, making yourself less nervous, and you will be a more engaging conversation partner. You'll more naturally take an interest in her interests, you'll be more friendly and less pushy, etc., and that shit helps. Also, getting your foot in the door is invaluable. The friendzone is not eternal (just don't be a nice guy).

That being said, if she's flirting with you, don't be set on only having her as a friend. Don't be afraid to flirt back/escalate/whatever. Personally, I would err on the side of over-flirting, but that's up to you.

Does this all make sense?