How do you stop a toddler escaping a new bed..?

[SunSoakedStone]

... and playing, destroying room or howling and banging on the door??

You can't.

You'll have to wait for the novelty to wear off.
You can stay in the room with him and read, cuddle, stroke etc until he calms down enough to no longer want to do those things.
Or, you can leave the room and keep returning to remind him that he shouldn't be doing those things.
Otherwise, you can shut the door and ignore him doing those things and let him wear himself out until he's ready to sleep.

You have to enforce a "stay in bed" routine from day one.

Be firm and don't send them to bed until they are tired