Is after effects any decent in making good looking movies?

The features of After Effects are like the name itself says, make the effects after the main basic edition of the movies. For example, fire, explosions, 3D animation, appear/disappear objects, shades, etc.
If you want to make a video without any complicated effects, then it's not necessary to use After Effects. Instead, use Adobe Premiere Pro so if you change your mind and want to add some effects then it will be easier to move your project to After Effects.
Also, After Effects is more complicated when you want to preview the audio and video together. It renders separately. Premiere Pro can preview both, audio and video easier.

Thank you Jodus, I've heard that some people "work" in AE, but I wanted to know the pro's and con's myself.

I work in AE myself, and it gets pretty complicated in the beginning, but if your willing to learn how to use the main functions first then give it a try. If your a beginner to video editing then I don't recommend the software to use. I would recommend using Adobe Premiere like how Jodus explained it.

Adobe After Effects is a video compositing program while Adobe Premier Pro is a video editing program.

If you're planning on making a video more than two minutes long I'd strongly recommend you to use both programs at the same time.

As Jodus said you should mainly use After Effects for effects and leave the other stuff (Arranging of clips, sound mixing, colour correction etc) to Premier as it's much easier and you can probably get a whole lot done faster

Thanks for the tip Zwift, I'll learn the basics of Premiere so I can have a nice basis to work on effects in AE later.

Also, thanks DatSkip. If I remember correctly you made a nice tutorial, I'll check up on it as well.