> I've been trying to learn to play the keyboard for a few years now and
> think it would be cool to eventually get to the point where am able to
> play as part of a group. The problem is that I really have no idea how
> to go about reaching this goal.

This makes it seem that you'd like to practice alone at home, until you know everything and can come out as a fully trained keyboard player, without having to face other people as a not-yet-fully-competent beginner. Sort of like, wanting to learn a language completely before trying to speak with anyone. But the thing is, you learn to play keyboard parts in a band by playing keyboard parts in a band. Go there and **try something**, and your learning will be boosted to a completely new level. One hour of actual real playing is worth ten hours of practicing alone.

> I'd think that a good way to practice would be by taking songs and
> simply playing them the way I would be expected to play them in a
> band. The problem is that I really don't know what that would be.

I think there's a mistake here. You're looking at entire songs, when you should be looking at *keyboard parts* of song arrangements. Look at what keyboard players do in bands.

There are many different categories of things keyboard players do. On an abstract level, the parts can be looked at from several perspectives: rhythm, harmony, pitch, texture, or the overall big story of a song. Or melody which has aspects of all of those. On a less abstract level you could think about things like (1) rhythmic comping, (2) background pads, (3) melodic playing. And then do it so that it supports the song and what everyone else is doing. 

**Fitting together rhythmically**: if you play rhythmic comping, make sure that it fits in with how the bass, guitar and drums are comping rhythmically. If you use a sound that has a clear loud attack, you have to think that it's a drum.

**Fitting together harmonically**: your parts have to be in  a *pitch range* that goes together with the other instruments. And it has to play the *right notes* so the overall chord makes sense.

**Fitting together melodically**: if your parts have a melodic element, it has to fit in with the lead vocals and any other melodic lead instrument. Fill in the gaps, don't step over the existing melody. Think about it as "counterpoint".

**Fitting together as a texture**: if there's a very bright guitar sound, you might want to play something more mellow or dark. If everything else is very thick, play something less thick.


Types of things to do on a keyboard are:
- (1) **rhythmic comping**. Like guitar strumming, but on a keyboard. This can be (a) two-handed left/right alternation ("stride"), (b) one-hand backbeat like in reggae, (c) chord arpeggios in a steady rhythm. You need to think about what the rhythm pattern is. If your group was a salsa band's rhythm section, which part do *you* play - conga, timbale, shaker, clave, cowbell? Do you **double an existing rhythm part**, or play **complementary counter-rhythms**?
- (2) **background pad**. You play slow pad sounds which create a harmonic background filling. Or even just single-note a high legato strings sound that stays as close to some single pitch as possible, in a voice-leading sort of way. In a chord progression C, F, Gsus4, G, C, your legato line would play the notes C, C, C, B, C. 
- (3) **melodic fills**. You play countermelodies and "fills". For example with a brass sound or a "heaven/fantasy bell".
- (4) **melodic doubling**. You *double* an existing melody and give it more power. Either in unison, or e.g. a third/sixth above or below.
- (5) **special effects**. Come up with a strange sound and add it sparingly somewhere in a song. It may catch the listener's ear and make the song memorable.
- (6) **full piano accompaniment**. All of the above at the same time. You play as if there were no other players in the band, and others adjust to your piano playing. This is typically done in slow ballads.