Hello to everyone. I decided to move from libGDX to lwjgl. I want to make games and overall learn a bit about opengl. The thing is, when i started with lwjgl tutorials i found this:

This tutorial will explain how to access OpenGL with LWJGL and is not intended to teach you OpenGL

Where could i learn how to use openGL and, specifically, 2D? I know i could just type "opengl tutorial" on google, but i'm not interested in 3D stuff. And i know that basically is the same process, still i'm looking for tutorials focussed on 2d in opengl. Thanks!!!  

Welcome.
http://arcsynthesis.org/gltut/ is I think one of the finest tutorials out there for OpenGL. The examples in the later stuff is mostly 3D, but the concepts are there and they way it is structured, you won't have any problem and it won't take any longer. The lighting stuff is completely 3D as I recall but you'll have to read at least the intro because it teaches shaders (which are hugely important).

Thanks. One more question. I read that slick-util is handy library for loading stuff (images, sound, etc). I have seen also this one that seems easier to understand and hack if needed (it even helps you with non-power 2 images). Which one would you recommend me?

Not a problem.
I'm afraid I've never used either, or any kind of similar library. I could recommend one but it would be nothing but a shot in the dark.

Well, i'll give glapp a glance. Thanks for your replies, i thought this land was desert.

Yeah, unfortunately there aren't quite as many of us here as at JGO but there are still those of us who believe. At least here you don't get people jumping down your throat telling you to use LibGDX.

Well, to be honest i'm one of those of who usually suggest using libGDX  . But time has come to go deeper.

I have noticed that the tutorial you linked is about opengl 3. I have no plans of using a greater version than one (besides, my computer can't support them). It is still recommended to follow it? Will i be able to apply most of its lessons?

Normally I would say, never learn anything but the basics from OpenGL 1.1, but if your computer can't support it ... (make sure you don't just need to update video card drivers first). If that is the case then I think you would struggle beyond tutorial 1 of arcsynthesis. (BTW I forgot to mention that @Princec ported that tutorial's code to LWJGL. The link is somewhere in the JGO forums if you do want to check it out).

To be honest, I'm not sure there are many good tutorials for OpenGL 1.1. There is the red book of coarse (online version: http://www.glprogramming.com/red/index.html) but I don't know of any others. The red book is good for OpenGL concepts though, I wish everybody would read it.