This seed was tested on Minecraft Bedrock 1.18.
View at Spawn:
View behind you at Spawn:
To get to the Mooshroom Island you are going to travel to -1400 800, so travel towards the trees you saw at spawn.
You will quickly come to a huge frozen ocean:
And then the Mooshroom Island in the distance:
This Mooshroom Island is a lot bigger than it looks from the picture below:
This is taken from the middle of the Mooshroom Island so you can get an idea of how big it is:
There are several cave systems on this Island as well:
This one leads to a huge open cave and a lava lake:
This one has a very small Lush Biome inside: