Helping a newbie

I've been binge watching the channel over the last week and thinking about buying something only for basically everything in the shop to be out of stock.

How often does stuff come back into stock? Is it a drop shipping situation or are they just slow to re-stock?

How does shipping work, roughly? Any idea on typical delivery times, especially for international orders (UK)? Are there any customs or import fees I should be aware of?

Also is the quality what you'd expect for the price, it's a lot more than I would normal / have ever spent on clothes so a bit concerned (I'm aware this is a slightly stupid question to ask on the subreddit for the channel cus you're obvs going to be positive)