href: Add a product to cart, and also link to another page

Hey! I am working on a commerce site(https://bymt.se), so I am using woo commerce. I don't really like the style of woo commerce, so I created my own pages with add to cart button etc.

I know that it is possible to add a href to my custom add to cart button. So when someone click buy, the product actually add to their cart. But I don't really know how... I also want them to be linked to another page when they have clicked the button!

I have grant you access! Please visit: https://bymt.se/webbpaket/ . Scroll down and you will see a few products. "Mini, Mellan, Stor". There is a button saying "välj". This means "add to cart".

So let say that they click "välj" at the product called mini. The product called "Webbpaket – (mini)" id: 208" get added to their cart. And they also get linked to the next step which is : https://bymt.se/funktioner/.

Sorry if I explain bad. Ill do my best!
Thanks for great support anyways.
Greetings, Marcus