You can kiss anywhere in virtually any position, but of course some places are better than others...
Here are a few kissing approaches
Kissing While Walking
Try a quick casual kiss, while walking. Simply carry on as you are but link fingers as a prelude to a kiss. Play with the fingers a bit, or use your thumb to massage her wrist. When you think the time is right, just stop walking, swing your head across and brush a kiss over her lips. With practice you can probably kiss even while walking.
Kissing While Sitting
Simply lean over and kiss her, or slide an arm around her shoulders (but that does make it more obvious); or
do what I think is so exciting: Push away a trendil of hair or run a finger down her cheek. You can even outline her lips with your finger and when you have her attention and she is looking at you totally mesmerized, lean over and kiss her.
You don't need to have any other part of your body touching hers, to kiss her.
Kissing While Standing
If you are both standing and she is against a wall or a door, keep on chatting about whatever you want to,
while your eyes signal your attention. Place a palm on each side of her head and as you talk, move in a bit closer and look at her lips. Then deep into her into her eyes, then back to the lips and move in for the kiss.
Kissing From the Back
Move aside her hair to kiss the nape or the lobe of her ear and then kiss her when she turns her head towards you. Let your hands slide around her waist to hold her close (but not too close)
Kissing While Slow Dancing
Some of the best kisses are on the dance floor, in the dim light, surrounded by strangers and pulsating music.
Lower your face to kiss her and then go back to dancing. Intersperse a hot kiss with some sexy dancing.
Kissing In the Swimming Pool ~ ooh... she's nice and wet!
Swim underwater to where she is, come out of the water, take a deep breath and kiss her before she has time to realize what is happening. Just grab her around her waist and hold her, to kiss her. The trick of course is not to drown, so try it in shallow water first!
Other than these basic approaches, you are limited only to your own ingenuity and resourcefulness. When it comes to kissing, just remember if it is a public place, don't grab her hips or fondle her breasts. Stick to only the kissing.
In reality all these things seem scary to you, if you have never kissed a girl. But once you do, everything becomes instinctive and easy. You go with the flow and do what comes naturally to you and to your partner.
However here are a few suggestions to get you started:
Put your arms around her waist, when you need to hold her close.
Slide an arm around her shoulder, and use the other to tilt up her chin, for your kiss.
Hold both her hands at the wrist, while you lean over and plant a kiss on her lips.
Pull her down onto your lap to kiss her (not ideal for the very first kiss, unless you both want it very much).
Approach her from behind, slide one arm around her waist and use the other to move her hair aside, to kiss her neck.
Brace your hands on whatever is near her, trapping her in the circle of your arms, then you can lean across and kiss her.
When in doubt, follow her lead.
Or simply let your lips do the talking till you are more familiar with each other.