For your first outing, first, try to pick a race with a starting weapon bonus: Nord, Orc, Redguard, Imperial, or even Dunmer. Second, take a class with that weapon skill as a Major (or create a custom class that uses it). Additionally, having a decent Agility attribute also affects how easily you hit, and a Nord or Orc will have a slight penalty which is generally more than offeset by their higher weapon skills. Third, when you get off the boat, locate Arille's shop there in Seyda Neen and buy one of that weapon. It doesn't need to be a good one, just as long as it's in that class. With a few accumulated bonuses, you should have almost a 50-50 chance of hitting with your chosen weapon.
When you fight, there are several factors to consider.
In Morrowind, your fatigue drops while running, unlike in Oblivion where you can recover fatigue while running, so you don't want to get into a fight while already tired out.
Next, there are three modes of attack: stab, slash, and chop. Certain weapons do very little damage if used in the wrong mode, and I generally just set "Always Use Best Attack" in the options menu, so I don't need to worry about my character trying to stab with an axe, or chop with a Spear. Sadly, that promising game mechanic was never fully developed, so there's no advantage to using the various attack types except to get the better damage numbers.
The amount of damage you do is modified by how long you hold back the attack. If you just "spam" the button, you only get the minimum damage for the weapon. If you press the attack button, but don't release it to "unleash" the strike until it is fully drawn back, you do the maximum number.
After a couple of combats for you to figure out the system, your starting character should have NO problems with surviving an encounter with the weak wildlife around Seyda Neen. I've ventured out with several characters, using the cheezy iron dagger on the table in the Census and Excise Office, with "Short Blade" taken only as a "minor" skill, and gotten by just fine, although the character missed a frustrating number of times. Also, remember that your character is faster than those Mudcrabs, and can run away if things don't go well. The other creatures are faster, and you may not be able to escape from some of them if things turn sour. The REAL test of a level 1 character's combat ability is the Smuggler Cave not far from the Silt Strider port. If my character can get through that alive (even if it takes several "ventures"), then I've made a "playable" character.