Hi!
I'm a noob too, but I (hopefully) will be able to answer your question. I have chosen Galek as my starter champion and I do not regret it one single bit. Most of the members of this forum disagree with my choice, so my answer is; pick what's right for you. Here are a bunch of stats
Galek: Heavy Single hitter, great for Campaign Grinding and Farming Fodder
Kael: Heavy AOE, good for the spider dungeon (I think)
Athel: Defense (???)
Elain: OP Heavy attack, but the normal attack is weak
Also, would anyone else prefer Galek? Imo, his skills seem pretty cool
His skillset is pretty similar to Kael, minus the poisons. And the poisons are why everyone likes Kael. You can, however, ignore Accuracy with Galek and go Off/Def masteries...it's actually pretty nice.
If you want to be the most efficient, go Kael. If you like to buck the trend, any of the other three work perfectly well. I started a F2P acct with Galek 100 days ago, got Arbiter on day 85, completed Doom Tower on easy, and hang out in Gold 4. But...Galek sits in my vault, because that's what you do with all the starter champs eventually.
I picked Galek and he still gets a game here and there in my roster despite other nukers having been built like skullcrown, coldheart, his "ultimate" variant, the other starters etc.
All the starters are good choices, and you cant really go wrong with whoever you pick. They all have use down the line in both campaign farming and for faction wars at the very least. My least favourite is Athel, probably because I haven't built her quite as well and therefore she feels weaker. Kael's versatility is obvious and I can see why he might edge the other 3 out.