No problem, I don't use WW myself, I just know it's out there and (sort of) what it does. JCMs are built into V4's geometry, and you will see what they do later. We need to stay simple at this stage.

I see from your screenshot that you are trying the V4 Basic Wear... a good place to start.

To get the clothing to change as you change V4's shape, this is what you need to do... I don't know what you actually did, so I'll go through it all from step 1.

1. Load V4 into an empty scene. Don't move her or pose her or change her shape yet.
2. Load the Bikini bottom, then click Figure -> Conform to... -> select Victoria4 -> click OK.
3. Load the Sports bra, then click Figure -> Conform to... -> select Victoria4 -> click OK.
4. Make sure that Victoria4's Body is selected, and on the Parameter dials, apply a Full Body Morph such as BodyBuilder (see attached screenshot). You should see the clothes change shape with her body. If it doesn't work first time, return the morph dial to zero, delete the offending clothing part and try loading it again.
5. Once that is okay, you can go ahead and shape her body, and pose her, and the clothes will (more or less) follow. With some poses, for example arms raised up, you will get some poke-through (in this case on the breasts). That's to do with those JCMs - and that will be the start of the next lesson!

Let me know how you get on...
Izi

"If I were a shadow, I know I wouldn't like to be half of what I should be."
Mr Otsuka, the old black tomcat in Kafka on the Shore (Haruki Murakami)