Hello,
First of all thanks for choosing our Theme, we are glad to be you in the WoodMart WordPress family :-).
To add different variations you need to create a variable product first.
To create a variable product you can follow the video in our detailed documentation on how to create a variable product:
https://xtemos.com/docs/woodmart/woocommerce-tutorials/variable-product/
To create size guides you can follow our detailed documentation in the following link:
https://xtemos.com/docs/woodmart/faq-guides/create-size-guide-table/
And if you want to ask anything else then please provide some relevant screenshots of the specific area to check it myself and help you out accordingly.
Best Regards.
.
