So how do I know whether the equipment item things are physical damage...etc?

When you hover over the item (on computer), or click it (on phone/tablet), you should be able to see the item's description. That will tell you how much of each stat it will be boosting.

So basically, the one that is the top one (eg. Physical Migitation) is that the one that boosts the most?

You should be looking at the equipment description, to see how the stat points are distributed, since that affects the amount of damage the different damage types will deal. The percentage boosts are general, and not specific to the damage types, while the stat points should match your element type.

If you read the thread I linked in my first reply, there is a section that talks about equipment.

Link: https://www.sylestia.com/forums/?thread=45988&page=1#6 Author: Rixva Time Posted: 4/27/2017 at 11:29 PM After Your Pets are Attuned ...continued Gear So many shiny things... Gear can make or break your battle pet. In order to be effective in battle, you need to make sure they're outfitted with equipment that plays to their strengths! So much to read, but it's easier than it looks! Hovering over each piece of equipment in your inventory will show you a pop-up box that explains the gears' stats. I'll give you a brief explanation of what you need to pay attention to! Pay attention to the color! -RED gear is Mythical quality - the best in the game, and only obtainable in the dungeons or from the barracks in the Lost Grove! -GOLD gear is Legendary quality - second-best, obtainable from mission satchels and boss battles in exploration! -PURPLE gear is Epic quality - middle of the road, obtainable from mission satchels and battles, and some merchants in the towns. -BLUE gear is Rare quality - not the best, not the worst, obtainable from battling enemies in exploration, and some merchants in the town. -GREEN gear is Uncommon quality - the lowest quality gear in the game, obtainable from battling enemies in exploration. What to look for in your Gear - Required Level: Your pet must be at this level or above in order to use the equipment. -Physical or Magical damage (Relic Only): Physical for Earth, Air, and Water ; Magical for Fire, Light, and Shadow. NOTE: Some relics deal both physical and magical damage - these are not as effective as they sound! -Stat Boosts: try to match these to your pets' proficiency points! When you're just starting, it's more beneficial to boost their best attributes than to try to cover their weak spots with gear. -The orange stats on the right are more of a bonus than anything - these probably won't make or break your pet, so you only need to worry about them if you're seriously strategizing. But if you're curious: -Physical Mitigation: decreases the amount of physical damage taken by your pet -Magical Mitigation: decreases the amount of magical damage taken by your pet -Critical Hit Chance: increases the chance your pet has of landing a critical hit for extra damage -Accuracy Bonus: decreases the chances of your enemies avoiding your pets' attacks -Avoidance Chance: increases the chance of completely avoiding enemies' attacks Now let's take a look at the specifics of the gear you need! Back to the top!

So for air, water, and earth, the equipments should give more to the strength stat, and relics should also give a physical damage boost.

For fire, light, and shadow, the equipments should give more to the intelligence stat, and relics should also give a magical damage boost.