drealmer7 gave a great response to this, and I wholeheartedly support roleplaying your character. Arcanum is especially rewarding for this, as things can go very differently based on how you act and what you decide to do. So absolutely keep that in mind as you create your character.

However, if you have not played the game before and don't know how important reaction is, I will clarify it a bit. Reaction determines how people first judge you when they see you. If it's high, they'll be real nice and maybe try to flirt with you. If it's low, they'll be rude and dismissive, and possibly even openly hostile (i.e. they will attack you). But, provided that a character is not openly hostile right from the start, it's usually possible to improve reaction by being very polite and submissive. You can be horribly ugly, or you can be a half-orc that everyone is racist towards, but if you suck up to them, they'll like you better and you can still talk to them and do business with them.

So a low reaction will not absolutely ruin anything, but you should consider it when role-playing. Do you like the idea of being a grotesque creature that everyone recoils from, at least initially? Do you want to play that way while also acting subservient so people will still deign to talk to you? Or maybe you want to respond in kind, with anger and threats? All of those are possible. But if you'd rather have people like you when they first meet you, then don't take a background with a reaction penalty.

One tip for new players concerning backgrounds and race/background mixing: if you take a race and/or background that lowers one of your starting ability scores below 8, it will also lower the maximum score you are ever able to obtain in the ability.

In other words, if you start with a human, all your abilities start at 8, and max out at 20. If you then choose a background that lowers your starting Charisma to 7, it will also lower your Charisma ceiling to 19.

Why is this important? Because getting an ability to 20 gives you a special super-bonus. If you get your Charisma to 20, none of your companions will ever leave you unless you ask them to. They might moan and complain, but they'll never leave. If your Charisma is < 20, they might decide to part ways with you if they don't like the things your character is doing.

This is true for every ability. You can find the list of super-bonuses in the manual.

Note that you can use backgrounds to raise ability ceilings as well. If you play a halfling with a background that raises Strength to 8, you can get the Strength super-bonus (eventually).

Sorry that I am asking again, but I thought about starting a mage elf then.

So would it be a wise decision to start with a certain background (for a newbie)? I have read some threads about typical mage background and the best seem to be "Sold your Soul" and "Only Child". I looked into those two backgrounds and they seem to bring heavy penalties to one's character. Thus I am a bit in a conflict whether I should take a background or not.

Personally I lean more to being a tank style type character, (But I always have done that style in Every RPG). But yeah guns are kinda butchered in the Game. And spell's can be over powered, so its kinda a toss up.

Backgrounds are optional. All of the ones that come with the game come with some sort of tradeoff, and it's up to you to decide whether that penalty is worth it.

Best bet is that if you choose a background, take one whose penalty is immaterial to the character you're trying to play. PE doesn't matter much if you're not a gunslinger, for example, and a BE penalty can easily be offset by the Purity of Water spell and/or a nice smoking jacket. And a CN of 17 would be all you need to unlock all of its benefits other than poison immunity — which, by the time you get that high up, is a lot less important than you'd think.

Your alignment determines which quests you may qualify for, who will agree to join your party, and (in certain very specific instances) the ultimate outcome of an encounter. If an initial penalty which makes you somewhat evil (and maxes out your potential good at 80%) is worth the MA equivalent of 4 spells, then go for it; otherwise, feel free to choose something else, or nothing at all.

I really just like to pick "Born under a Sign" background.

Mages are helped by Willpower, Constitution (for the Stamina, and Stamina regen) and Dexterity. Mages don't need as much Intelligence (Mages really don't need this at all - what does that say about them?) or Strength. Beauty and Charisma are a bit different. Nobody really needs them, strictly speaking, but they have a significant impact on your interactions with NPCs in the world, so it's your choice.

You'll probably want a background with +WP, +CN, or +DX, and also -IN, or -ST. As TwoHandedSword said, it's perfectly fine to make a character with no background.

Point of clarification: IN does affect mages in one small but significant way: by limiting the number of ongoing spells they can have open at once. 8 IN allows for two spells, 12 gives you three, etc.

It's possible to maintain a maximum of five spells (at 20 IN), although the Fatigue (FT) costs are likely to be too demanding to do so indefinitely (at least, not without having a supply of FT potions on hand).

Also note that this has no effect on one-shot spells such as Harm or Minor Healing; even with a full complement of maintained spells, you can still cast those (FT permitting, of course).

I always liked "Nietzche Poster Child" for a trait. It felt like it made the character really mine. I get more exp - but i also fail more often. However there's one thing to consider here - there's not a single one trait, that makes your character better. It just makes it better at one thing and worse at other.