Maybe not the actual answer to your question, but you can easily locate a Pillager Outpost using this Pillager Outpost finder site. The only thing you need is your world seed.
As far as I know Pillager patrols are spawned randomly, there's no reliable way to get one outside of their outpost.
From Minecraft wikiaWiki:
Patrols spawn naturally after the world age reaches 100 minutes (5 in-game days), then after a delay between 10–11 minutes an attempt is made to spawn a patrol with 20% chance of success. After an attempt is made, the delay is reset.
You also need to check that:
In Java Edition, patrols never spawn if
/gamerule doPatrolSpawningis set to false.