Technically, you can do this. However, bear in mind that not all themes support WooCommerce and you might not get a matching look on the WooCommerce pages.
If your theme is incompatible with WooCommerce, you will get the default look of WooCommerce without all of the styling of your theme. If that is not an issue for you, then it will work for you.
Alternatively, you can also install a free theme like Neve which supports WooCommerce from the get-go and will style all your pages according to the theme styles.
Yes, but it depend on your theme