So im not so new anymore but, one thing ive never understand is weapons and battling. Can someone explain to me like im five :>

And can someone please tell me how to get stronger weapons with higher tier?

All with love and blessed be <3

First is to be able to determine your pet's tier and stats, which can be found on your pet's page. You can only equip weapons at or below your pet's tier. You can find a total list of weapons here:

subetalodge

In order to use a weapon, you need to build a weapon set in the armory. You can add weapons into your armory through your inventory. Always check in the inventory screen to move to the armory - the stats of the weapon, the tier, if it is infinite use (never breaks), semi-breakable (will last x number of turns in battle before breaking), once per battle (will disappear after one turn but is still in your armory) or is single use (disappears forever after you use it and you need to buy another). You can have up to 8 weapons in your weapon set for battle. You can only equip one healer, stealer, and freezer at a time. An item that is identified as a stealer, freezer or healer will be tagged as such in the armory. Once you build your weapon set you will be able to challenge an opponent.

On the screen where you go to battle a challenger, you will see two options - battle with default set or choose weapons. In the armory where you first set up your battle set, you have the option to edit, delete and make default. Default will automatically throw you into the battle with the weapon set you selected as a default along with the pet name you select in the drop down menu. GA users have the ability to make 5 weapon sets while non-GA users can only make three. If you make 5 sets with a GA and then your GA expires, you will still have those 5 sets saved and available as long as you don't delete one.

The choose weapons button will take you to the setup screen where you will see all your eligible battle pets, scroll sets and weapon sets to choose from. In order for a pet to battle, they must be happy and fed. It also gives you the ability to turn pre-select on. I highly recommend doing this first. Instead of choosing your weapons every turn, pre-select will default to having the first two weapons in your weapon set and first weapon in your scroll set already selected before you hit the 'make your turn' button. It's nice to have pre-select active so you don't have to choose your weapons every since turn but you can still always change what weapon you want to use by manually selecting it in battle.

Scrolls are the next biggest part of battling. They rely on your pet's AP. They can be used regardless of tier, but you can only use a scroll set that is at or below your pet's AP. AP is obtained through books. Every 16th intelligence point gained through reading a book will give you AP. you can gain intelligence many ways, but only reading a book will give you AP. Say you use boosters to give you 50 intelligence and then you read a book for another intelligence point, your pet will then gain 3 AP. You create scrolls similar to how you did in the armory but in the section 'scroll library'

The last thing is potions, but it can be very confusing for your first time battling. The bare minimum you need to battle is a weapon set. For more information on battling, you can also check these guides here

Feel free to reach out if you have any questions! Happy battling!

I will add that when you train pets only train level WHEN NEEDED. If you train it too far it costs more sp and time for your other stats. You can train other stats up to 2.5 times your level, for example a level 10 can have 25 to each stat before level needs upped. Read to your pets as often as possible. It's also not a bad idea to set goals of who is a main battler and secondary. I have a goal to get all my pets to 100 in each stat so they can all participate in event battles a little bit. As Wesker said do read that linked guide for some good pointers.

ETA: Do your Shinwa quests as some of her items are stat boosting. And if summoned for oracle make sure your main battle pet is set active before turning it in so they can benefit from the random boost.