So I know everybody prob done watched this series by now I just finished episode two and don't know anything about Wanda other than marvel movies .. but if she can control reality why didnt she just that against thanos
Short answer....the plot didn't require it yet.
Longer answer....she most likely can't manipulate reality unless she's focused. And even then she can only do it (so far anyway) in a "bubble" like the town.
Fred.