Hi and welcome, hopefully someone will link in the comprehensive food guide for you soon (sorry can't copy links on my phone,
@Siikibam @Piggies&buns can you post the link?).
Cucumber and bell peppers are good every day veg, along with some sort of leafy veg- coriander/cilantro and some lettuces (romaine, little gem, babyleaf) can be fed daily, usually alternating with a bit of higher calcium leafy veg like spinach, kale or parsley fed once or twice a week. Some piggies also enjoy green beans and celery. Higher calorie veg like babycorn or carrots should be fed very sparingly, a very small piece as a treat once or twice a week but no more often than that. Fresh grass can replace the leafy veg too, if you have access to clean fresh grass that hasnt been treated with chemicals and isnt accessed by dogs- grass is what they would mostly eat in the wild! And of course hay should make up most of their diet, 80% of their food should be hay, and very few pellets/nuggets- a tablespoonful a day, no more.