Both are offensive spell i know but I find it hard to use conjuration at the early levels so my plan is to use destruction as my main magic first then level up conjuration a little later but will there be any penalty for not using it now??
Me currently level 3

its great

fire deadra + fire spells = tank immune to ur damage
frost for forst, storm for lightning you get the pic

my level 48 mage can summon 2 storm golems and is a lightning GOD he is almost unstoppable

No there will be no penalty, though your conjuration will most likely be respectively weak to the enemies you face at first.

only if your summoned dremora has mastered the dark hadao

Also, I was wondering if there is any follower that you can recruit that would give free conjuration or destruction training?

By weak you mean my summoning familiar getting one hit by a freaking bandit !

I prefer pairing Destruction with Illusion.

Don't bother with familiars, go for Storm Atronachs as soon as you can afford them Magicka-wise.

Conjuration works the same way as Destruction in that you must upgrade your spells as you take the half-magicka perks. Conjuration is leveled up by your conjured/raised companions engaging in combat and also being in combat with a bound sword/axe/bow. (Another way is to cast Soul Trap on an enemy, even if that person is dead.) If you'd like to use them both together, here's a list of suggested conjured companions to use as you level it up.

Novice - Familiar
Apprentice - Flame Atronach
Adept - Frost Atronach
Expert - Storm Atronach
Master - Dremora Lord

A good time to conjure them is if you know you're going to be coming into contact with enemies, or right when combat starts, as the more time that they are in combat, the more your skill raises.
Also, I'm not sure of where I got it from (All I know is that it was a quest), but I have a Conjure Flaming Familiar spell, in which a fiery wolf comes and explodes in front of the target, it's great for low level mages who are having problems with big groups of enemies.

The dremora lord is actually a expert level spell.Only the thrall spells are master spells.

I played my mage to lvl 61. Destruction, conjuration, alteration, enchanting as main skills. Very satisfied.

Playing destruction/Conj at the mo with a bit of alchemy, enchanting and a little resto thrown in for good measure. Damn good fun to kill a bandit and res him to kill his mates while you blast them all from afar

I'm completely happy with my mage using Conjuration, Destruction, Alteration and Enchanting, which leveled mostly from recharging with soul gems. I threw in Sneak and it's been great. Choose your perks wisely to keep building your mage to handle anything.

Exactly my main character, Conjuration and Destruction. At lower levels, the summons are great to distract enemies so that you can cast the destruction spells at them, later your summons are so good you don't even need to use destruction any longer. Works very well.

summon atronoch, switch spells, summon blade right hand (or lesser ward if less than friendly mage encounter lies ahead) and blast with firebolt or lightning bolt from left hand.

I do it all the time... on a guy who wears heavy armor enchanted to assist him and who wields a lesser ward (steadfast is really just incredibly magicka draining) like a shield against mages instead of a sword in his right hand.

on this run through my conjuration/destruction character is only level 21 and already has conjuring 65/destruction 40 without forcing or paying to train levels. his restoration is like 35, though... so this character becomes all about balancing the perks in magic trees and heavy armor.

yay steed stone.

good luck with whatever you decide.

Yep. Two dead thralls who can conjure, a follower who can conjure and a dog. 8 member assault team. Red dots are gone before I can figure out where the threat is coming from. Took a long time to get there so it was very satisfying once I had arrived.

You can't use AOE spells with summoned creatures though, they will turn on you in a heartbeat

Exactly the same as above. The combination is fun and deadly! If it gets too easy, conjure up a bound bow or sword and use those for a change.