Building my first actual team #1: Set up pokémon

I'm not really a competitive person so I never really did any online battles except against some friends.
I did those with just pokémon I like and they had no chemistry whatsoever.
After all these years I've decided to finally make a team.

I'm looking for a full team of 6, mostly for single battle with no restrictions and sometimes for single battles with special pokémon banned.
The team so far only has a Mega Absol (which will be a sweeper to come in mid/late game) and a Gardevoir which I'm not sure how I want her yet, might switch in between Absol and her for Mega.

Right now I'm looking for a set up pokémon ... one with spikes/toxic spikes/stealth rock/etc, maybe a leech seed and/or a status move: thunder wave or some powder stuff. (preferably a bit bulky)

However I do still want to enjoy myself so I got a list with Pokémon that are okay for me.
I was planning on Diancie with stealth rock since she's rather bulky, she'll also have toxin but I don't think she's allowed when restriction rules are chosen.

Here's the list:
-Lapras
-Vaporeon
-Espeon
-Suicune
-Lugia
-Celebi
-Gardevoir
-Mawile
-Flygon
-Banette
-Absol
-Latias
-Jirachi
-Lopunny
-Lucario
-Glaceon
-Leafeon
-Frolass
-Whimsicott
-Lilligant
-Zoroark
-Volcarona
-Virizion
-Meloetta
-Braixen
-Sylveon
-Diancie
-Primarina
-Lycanroc (night form)
-Lurantis
-Tapu lele
-Magearna
-Poipole
-(vespiquen .... she's still on my doubt list)

The thing is, except for a few pokémon I'm not sure how I can use or build most of the ones in the list. I also don't know what Pokémon are used the most by others as well as which ones work well together.
Every time I build a pokémon I never think of a team, I always build them to be the best (for me) on their own, not as a teammember. Guess me not being a teamplayer myself might have something to do with it :D

If anyone feels like they could help, feel free, either way thnx for reading ^^

A good way to start getting ideas for sets for Pokemon is to look at its Smogon StratDex page, as they have sample/standard sets listed with explanations and other potentially useful info. You don't necessarily have to copy the sets exactly or do everything else listed on the page, but it at least makes for a good starting point, to get a feel for what kind of thing or things one can do with a 'mon.

The Pokemon Global Link also keeps track of usage statistics for Battle Spot:
Singles
Doubles
You can see here what are the most commonly used Pokemon, what are the most common moves/natures/abilities/items they are run with (even with percentages for each), as well as what Pokemon are most commonly found on the same team as it, which Pokemon it most commonly KOs, and what has most commonly KO'd it.

The Pokemon that a typically banned are the box legendaries and the event only 'mons. On the list you have there, that means that Lugia, Celebi, Jirachi, Meloetta, Diancie, and Magearna are banned in the "no 'special Pokemon' " version of Battle Spot.

Nah said:

A good way to start getting ideas for sets for Pokemon is to look at its Smogon StratDex page, as they have sample/standard sets listed with explanations and other potentially useful info. You don't necessarily have to copy the sets exactly or do everything else listed on the page, but it at least makes for a good starting point, to get a feel for what kind of thing or things one can do with a 'mon.

The Pokemon Global Link also keeps track of usage statistics for Battle Spot:
Singles
Doubles
You can see here what are the most commonly used Pokemon, what are the most common moves/natures/abilities/items they are run with (even with percentages for each), as well as what Pokemon are most commonly found on the same team as it, which Pokemon it most commonly KOs, and what has most commonly KO'd it.

The Pokemon that a typically banned are the box legendaries and the event only 'mons. On the list you have there, that means that Lugia, Celebi, Jirachi, Meloetta, Diancie, and Magearna are banned in the "no 'special Pokemon' " version of Battle Spot.

Click to expand...

Apparently it doesn't matter anymore because I can't use my pokémon in the battle spot for whatever reason there might be for it.

Sadly enough these "special" pokémon can't be used for certain in game things either which is honestly really stupid.