I could go into history buff mode and give you an accurate description of what vikings would have worn if you want, but if not I'll try not to be that guy.
Please do if you can spare the time.
If you really want to reenact, wear no armour or a chainmail shirt for a wealthy man, use a spear or axe rather than a sword unless you're trying to be a chieftain and carry a round shield. Helmets probably were goggled, spangen type and could have chainmail to protect the neck, although they've foud only one so far if I'm right. That's about true for the middle viking period. Kite shield and simple helmet with noseguard for late period. Longer mail skirts. Too much leather is only for Conan.