Hello
I am seeing one girl for three months, every time I call her a cup of coffee, always respond. A few times we played well as tennis. In fact, I like her company and I am willing to invest in the relationship. Now there's one man apear so to speak player, and once they went on a drink. She told this to me. I asked her if she likes him, she said she does not know.
Whenever I'm in her company, tells me everything.

How to, go ahead with this girl?

Don't be threatened by having another dude in the mix. It was a mistake to even inquire how it went with the other guy. When you are with her, focus on making your time together about the two of you. As far as you're concerned, she doesn't have any other love interest (no boyfriend, husband, etc.). Even if she did, and you wanted to close on her, then you should rarely observe the significant other (only if you're doing bf destroyers, which are...questionable by my moral standards).

Point being, you need to just keep running game on her and feel it out. If you like her, then continue investing time.

Now, some important things to keep in mind...

DO NOT get all mushy before she does, and be careful HOW you say things. Don't act like a pussy about things. Openly express yourself when it is appropriate, and don't say it like you've just recently become a high school freshman.
DO NOT ask about her relationship with other guys. That is her business. It might be a little different if you were dating her. In this case, you still have to remain indifferent and confident that she will not betray your trust. If she does, and you find out, that's her bad.
DO NOT be a dick about it if she chooses to get friendly with another guy. Be aware and supportive, but don't talk to her about it if you wish to remain friends. If you don't, then stop talking to her.
DO continue having fun with her! If things are going well and you want to have an actual relationship with her, it will happen.
DO listen to her, but be careful that you don't become the shoulder to cry on.

Just a few thoughts. If anyone wants to correct some theory in there, be my guest! I'm learning, too!

Thanks man

One more question:
Is that wussy behavior....
This girl is now going on college and she have some problems to sign in college. And i am helping her to sign in (looking for some information and asking my friends about college).

Anytime a girl mentions another guy to me I either immediately respond with, well I know he's not as awesome as me cause I'm 'Krush' (name there). I just basically turn the conversation back to me and forget she even said anything.

Wait are you guys going out? If not then what relationship is this that you speak off?

Sound to me like your becoming like her gay best friend that she tells everything to.
Have you even escalated with her? I mean that's 3 whole months.

You have to feel it out man. Put yourself into the mindset of being a confident, assertive man. You are okay with or without her, but you would like to keep her around (you don't "need" her).

Another thing to keep in mind is how primitive we can be. Women want a protector. Sticking up for her is a good thing. Doing unwarranted favors...maybe. She might want to "do it by herself" because she's a "self-sufficient woman." I tend to avoid helping out unless asked or feel like she is implying that she wants it.