Mei Foo Station have 4 platform.It is West Rail line platform 1(to Tuen Mun District)West Rail line Platform 2(to Nam Choeng District)
Tsuen Wan line platform 1(to Tsuen Wan District)
Tsuen Wan line platform 2(to Central District)
you should don't worried because Tsuen Wan line and West Rail line have the pedstrain footbridge conecting.you can ask you friend dating you at which line platform and which exit.
Hope above information can help you!