Hi Ulag. Nice to "meet" you. As far as which subclass to pick, it's a matter of how you want to play. The warlock is a heavy damage dealer, so plays an offensive role. He is a mage, so he still has weak defenses. Locks tend to be one of the first classes targeted by the enemy. The conj is typically a support role as he heals everyone else. they are best played in a very conservative / defensive style. They tend to be the #1 enemy target. The conj can play what is called a warjurer setup which is more offensive skills. But this is usually looked down upon as they are best suited to the support role and opther classes, like the lock, deal dmg much better.
When you get access to the rest or the forum, do a search for 'conj' and 'lock' You should find several good posts which talk about how each is played. They should help you make your decision.
Welcome to Regnum, see you in game sometime.