Here are some good veggies to try:
Asparagus, broccoli, brussel sprouts, cabbage, corn, cucumber, kale, peas, peppers, potato, pumpkin, spinach, sprouts, squash, tomato & zucchini.
Here are some good fruits to try:
Apple, banana, blueberries, cantaloupe, cherries (without the pit), coconut, grapefruit, kiwi, melons, mango, oranges, papaya, peaches, pears, pineapple, plums, raspberries & strawberries.
As far as other foods to try...
Pasta, beans (cooked), sweet potato, brown or wild rice, eggs - scrambled or hard boiled and be sure to give the shell of the egg (just break it into as tiny as pieces as you can) if you scramble the eggs...the extra calcium is good for them.
Generally, if the food is nutritious & wholesome for you, it is safe to feed your fid. Some fids have differnet diet requirements and with a budgie you don't want to over do nuts, they don't have the high fat requirements that macaws do.
I stay away from peanuts because they have a high level of mold. I also don't feed iceberg lettuce or celery as they don't provide a lot of nutirition.
One very popular meal with Toby is my Birdie Burrito.
We use soft and hard corn tortillas and stuff them with all kinds of good foods. It could be a veggie mix (if you mix in a little bit of shredded cheddar cheese and zap it in the microwave the cheese will help the veggies stick together). Or pasta burritos or fruit burritos or ..... The other day I put a light coating of all natural (no sugar) peanut butter on the soft shell and sprinkled chopped nuts and celery folded it in half and cut it into 4 pieces, he went crazy for it! The possiblities are endless!
I think I rambled again
but I hope it helped.