A wizard / Fighter is a bit of a hard one to play at low-levels. Even so, there are some basic things you could do...
True Strike,
Shield and
Mage Armor are always nice to have around.
Magic Weapon isn't bad either, even if it only gives that +1 bonus.
Other than that I would suggest sticking to a more traditional Wizard style of buffing your friends and using
Enchantment &
Necromancy school spells on your enemies. Once you have 5 levels of Wizard and 4 levels of fighter you have a fairly balanced set of combat skills and spells, and those close-combat encounters aren't so bad anymore. I suggest concentrating on two, maybe three, schools of magic. You can occasionally take something very useful outside of these schools, but sticking to a specific area gives you a better fighter / wizard.
The other option is going for the Fighter levels at this point. You can do a nice bit of damage once you get
Weapon Specialization and add it to some buffs. Like mentioned above: you probably want 1 more level of wizard first, whatever you do. After that it's your decision:
- Figther with a few aces up your sleeve
- Wizard with some experience with close-combat
- An archer with a range of nasty surprises
Those are basically your options. At the moment one of my players is at Wizard 4 / Fighter 2, and he is still struggling with the concept. He has a nice array of defensive spells and feats, but the offensive side is still somewhat lacking. I would imagine that his character will become truly powerful around lvl 10, when he has Wizard 6 / Fighter 4, and that's what he is aiming at.
Also: if you can get your hands on a
Mage Blade it is a must have for a Wizard / Fighter. The enchantment gives a +1 attack bonus / 2 levels of arcane caster you have, and it comes with a +X blade, so it's a very nice sword

.