You can create the line using a shape layer with an animated gradient fill, or a shape layer with fractal noise applied and colorama, or . .. or. .
The other technique, the appearing text and images, is nothing more than animating position and masking. A track matte would be easiest.
The rest is just keyframing. There's nothing complex enough in the sample video to require tracking. Then a little glow or some duplicated layers with blur and blend mode combinations.
If you have no clue what to do with these suggestions try starting at the basics to learn keyframing and masking. Figure how those basic elements works, report back, and I'll point you to a fractal noise / colorama example.
Here's a page full of links to After Effects resources, such as tutorials: http://bit.ly/c06llu
Otherwise I would just follow Rick's advice and animate a mask over a shape layer with colorama, an animated gradient and/or fractal noise on it. It should be really simple. You're not trying to do something more complicated like make the light draw text along with your finger are you?
I will start tomorrow learning those basic tutorials.
I really just want to make that line (because its very famous in Portugal, and once people see it in wedding they will start smiling!)
Then I will report you back for you to help me!
I really just want to draw that specific line ( just similar colors and if it's 'shinning' like the original, better, because its very famous in Portugal and will make people smile for sure on wedding)
I have to watch tutorials, because I just have couple of weeks till wedding!
The animations I will make on Final Cut, where I am better...
If you just want to draw the line use the shape tool and fill it with a gradient, then apply glow.
A careful look at this screenshot tells you all you need to know. Layer 2 is a simple shape path drawn with the pen tool and colored with a gradient. The gradient editor is visible. You can animate the colors. To layer 2 I applied glow and a directional blur.
Layer 1 is a copy of layer 2 with slightly different glow settings and a blur of only .5. The blend mode for both layers is set to ADD and they are laid over a screenshot of your sample video.
Should take you about 5 minutes.
Rick's method is fantastic, but I've had trouble with the glow effect due to the way it treats different colors. If you notice it seems to make some of the colors glow more than others. You can play with the settings, but I've always found it to be easier to do this kind of thing with feathered masks. That way your masks are already there and you can do all your animation on one of the shape layers and then just copy the keyframes over to the duplicate when you're done. Doing it this way might look a little more similar to your example, but of course it all depends on what kind of look you're going for. Anyway, here's a little tutorial for the way I would make this.
but I've had trouble with the glow effect due to the way it treats different colors.
Simply duplicate the layer and blur it, then use Add or Screen blending mode.
Thank you so much for the trouble, you both had lots of trouble making this, I can't thank you enough!!
I will try it this week following your tutorial and BenMarkus also!
Thank you both for your time!!
I will report back if I will find any issue!!
Thank you so much!
I was able to make the line!
Actually during the process (trying to find your methods) I discovered new options!
Can you suggest me one thing? What's the best option for having a black background like that? Filming on the dark? Filming with chroma key and then apply dark background?
Filming in a dark studio with a black backdrop is by far the best. Greenscreen (chroma key) is only a good idea if you have a professional grade camera and can shoot at a high data rate. Greenscreen is a make do solution with any other kind of gear.
If you can afford it, you want a black fabric called Duvetyne. We use it all the time when we shoot stop-motion in a studio setting and we don't want any spill to show up on a black background once it's been lit. Here's two websites that sell it, but I'm sure you can search around for better prices.