The first thing you must do is create a squad. As a starting Level 1 trainer, you can choose up to a maximum of 15 Pokémon, including gender. You must also indicate the Level of the Pokémon at all times. For example:
Male Pikachu (Level 1)
Female Butterfree (Level 1)
Genderless Voltorb (Level 1)
You may also give your Pokémon a name, like Ishizu: Female Skitty (Level 1). You can check the Pokémon Level Acquisitions section to check to see which Pokemon you are allowed to have on your squad for your current trainer Level.
Level 2 Pokémon in Initial Squads
Since a Level 1 Trainer starts with a maximum of 13 Pokémon, a Trainer can reserve only 2 Pokémon of those 13 from the Level 2 acquisition list, except for the Pokémon listed in color (either blue, green, red or purple). When a trainer goes up to the next level, so does the Level 2 Pokémon (to Level 3, 4, and so on).
Now if both your "initial" Level 2 Pokémon are on a trainer's squad at the same time during a battle and one of them is used, there is a chance that the Pokémon may become unruly and may not listen to its trainer. So beware of this, trainers.
For each Pokémon, you can choose to append a signature move to that Pokémon. If you don't want to make a signature move, you can say "No Signature Move" below the Pokémon's name. Read the Signature Moves section for additional information regarding Pokémon signatures. All submissions are to be posted in the Squad Submissions thread to be approved and/or disallowed by a League Official. Make sure you post your Pokémon name and signature move on separate lines in your squad post.
For every Level you go up, you can add up to 3 Pokémon to your squad. You may also win additional slots through tournament promotions. If you don't remember your maximum number of Pokémon, you can always double check the League Table. Gym Leaders and Trainers automatically get an additional 3 slots for their Gym Pokémon in addition to the level bonuses that they've already accumulated. Pokemon that were in your squad before you levelled with automatically gain a level (so if you were a level one trainer with a Poliwag, said Poliwag would raise to level two when you do).
Each of the 3 additional Pokémon that you add to your squad must be added at Level 1 and be obtainable at your new Trainer Level.
If you wish for the new Pokémon to "catch up" to your current Trainer Level X, it has to be on your squad in X-1 matches (for example, 2 matches to reach Level 3). Each match that Pokémon finishes, it then increases it level by 1. These matches cannot be equilevel, equievo or equiall at a higher level than the pokemon actually is, or it will not count towards the Pokémon's level up (no levelling a level 1 Axew up by using as a Haxorus in equiall 5).
Also when you reach the next Trainer Level, and a Pokémon in your squad evolves at that level, just post in the Sigless Squad Submissions thread saying you want to evolve your Pokémon and display the evolutions just like posting an addition to your current squad. An example of the format is the following:
"I'm evolving these Pokemon in my Squad:
Ishizu: Female Skitty -> Female Delcatty (Level 3)
Remember, for a Pokémon that needs happiness, trading, or a stone to evolve to the next level, they don't need the particular item. It usually takes 2 Trainer Levels further than the level of its previous state for the evolution to happen. For example, you can obtain a Growlithe at Trainer Level 1. You can evolve that Growlithe to an Arcanine at Trainer Level 3 without a Fire Stone. Check the Pokémon Level Acquisitions table for the complete list.