Some questions from a beginner

[Shapeshifter878]

What is the minimum amount of points/army to make for a fun game? I read at least 1500 pts somewhere.

Is it possible to add "Dogs of War" units to your army, like in Warhammer?

In the Chaos section of the rulebook there is a description of the different Gods(Khorne, Slaanesh, etc). Do I have to choose one of these or does it not affect the gameplay?

If using Ogres in a Chaos army, does their special ability apply to my own units? In other words, do I have to keep them at least 20 cm away from my humans or else the ogres will charge them?

Thanks

[captPiett]

Welcome aboard. 

Some short answers:
You cannot add dogs of war units in a tournament-type warmaster game like in warhammer. However, there is a dogs of war army list, and nothing says you can't add special units into your armies in friendly games. You just have to be aware that the army you create might suffer from balance issues.

The chaos factions don't affect game play

Ogres only have to charge opposing humans, not ones on their own side, so group them as close as you want. You can put ogres in the second line of a brigade to prevent them from charging when you don't want them to. No LoS, no charge.

[Stormwind]

We've been playing starter games of 1000 points to get into the rules.

You can go as low as 500 points by omitting the "you must have a general" rule and instead having a single hero.

Generals can cost up to 200 points so the smaller the list, the bigger the proportion of your points eaten up by command stands!

[jchaos79]

Agree with all the answers

[Shapeshifter878]

Thanks for your answers!