There's an item in one of the lockers (women's I think) on the 1st floor that has a good persona in it you can pick up. You'll need Star cards for it, but it's Iris, who is good, and an earth user (works good on Maya too, best on Ulala).
So, a primer for Persona 2:
1) Equipment. Focus on armour, as mentioned. Weapons are good if you have extra money, but not necessary unless you have good physical skills (Triple Down on Katsuya, for instance)...and even then, good magic should beat good physicals any time.
2) Fusions. Fusions are excellent. They have some patterns, but the most basic one is two skills of the same type cast together (so agi+agi, bufu+bufu, etc.). This will result in a fusion of the same element, stronger than the two that went into it (based on the strength of the last skill used, so agi+agidyne will be stronger than agidyne+agi). Using a fusion to finish off a battle will sometimes result in a mutation, with a higher chance on a persona a character has higher compatability with (i.e., Moon or Hermit on Maya, Star or Temperence on Ulala, Death or Devil or Tower or HangedMan on Baofu, etc.). Mutations can be rank up (+2 ranks), parametres up (I have max stats on the starters in my one save, for instance), new skill learned (every persona except for a select few special ones have a special mutation skill, usually good), or special attribute learned (limits, of sorts). The system is also nice, in that it allows you to set the fusions up very well, so no issues being interrupted like in some other games.
3) Personas. First, personas will boost attributes on level-up. Moon and Star boost AGI, Hanged Man boosts LUC, Justice boosts STR, etc. Since this is the only control you have over the stats of everyone but Maya, make use of these. Each arcana boosts a specific stat, so make use of these right before level-ups. In addition, each character has dominant arcana - these arcana have reduced SP costs for using the persona skills (so Moon or Hermit on Maya, Strength or Justice on Katsuya, etc.). Make use of these, as it helps your SP stay nice and high during and between battles.
4) Maya. Pump her TEC and VIT, as these will boost defenses, HP, SP, and SATK (magic damage). Combine with the above to get a fully customized Maya with awesome stats. Also, do note that LUC is actually an important stat, so neglecting it isn't a good idea - it affects drop rates, criticals, status rates, etc. Pixie, a low level persona you can pick up, gets super awesome LUC that can help boost a low one.
5) Setting up for now. Make a contract with a demon, preferably the highest level demon in the dungeon (that is most common - since you want to encounter them often). This requires you make them interested, request a contract, and be of a high enough level (equal to theirs) to make it work. When you encounter them again in battle, make them interested, and they'll give you cards of their arcana, as well as free tarot you can make into any arcana in the Velvet Room. Try to make the following personas:
DEATH Hel (for Baofu - and keep her, she is EXCELLENT for fusions)
STAR Iris (for Maya...and later Ulala)
STRENGTH Ryume (for Katsuya)
EMPEROR Airget Lam (+1 TEC on level-up, has some decent earth spells, cheap)
STAR Kimnara (+1 AGI, also has level 2 fire spell and a decent healing spell, and is cheap)
SUN Surya (+1 AGI, has good fire spells, as well as some wind)
HIEROPHANT Genjo (+1 STR, gets media)
None of these block wind (Airget is weak, so don't use him in the battle; as is Iris) These are fairly low level personas that will help a bit more than what you have. Hel is especially nice. Try doing some fusions in battles to end them, and mutations should come. Level 17 or so is what I'd suggest.
6) Rumours. Walk around and talk to everyone in the city, including going to the computer cafe, after every dungeon to get new rumours to spread. These can upgrade equipment stocks, provide additional services in shops, and other cool stuff. Do this, it helps.
That's...about it thus far. Just feel free to ask any other questions if you want!