The first advice is making smoothies that you like. Getting nutrition during this time not only can help fuel but it can help bring down the inflammation post-surgery.
Aim for recipes that include at least 300 calories such as this one:
Try adding some of these foods to bring down the swelling: https://www.nutriliving.com/blog/top-10-anti-inflammatory-foods
You can search for more recipes here: https://www.nutriliving.com/recipes