Hey, you should probably check out this thread, which is very helpful when it comes to doubles.
[spoiler]https://forums.pokemmo.eu/index.php?/topic/53110-double-battles-viability-thread/ [/spoiler]
If you're completely new to competitive, then I recommend you to check out this:[spoiler]https://forums.pokemmo.eu/index.php?/topic/8898-basic-team-building/[/spoiler]
Good luck!