Environment

Cage

Your bird’s cage should be at least 18x24x24 inches large, and the bigger the better. It must be more wide than tall with horizontal bars no larger than half an inch apart. Circular cages and ornate expensive cages are a waste of money, as a budgie could get hurt in a nonrectangular cage. Make sure your cage is not made of harmful materials such as zinc, brass, or lead.

Line the cage with paper towels, newspaper, copy paper, etc to catch droppings for easy disposal.
The cage should be against one or two corners of a room and in an area where people commonly hang out. DO NOT place your birdcage in the kitchen, as fumes from teflon pans and cooking oils could be deadly. Temperatures should be at least 80F.

Perches

Perches provide a bird with places to sit and sleep above ground. Avoid perches made of prunus tree, oak, and concrete, or anything that’s not birdsafe. Smooth wooden/plastic dowels hurt your bird’s feet and could give them foot issues; be sure to have textured perches in there for your little buddy’s feet. You may have heard of sandpaper perches that are supposed to file your bird’s nails, but they can cause foot issues and harm your bird’s skin.

Toys

A budgie needs toys to stay stimulated otherwise it could resort to plucking out its feathers. There are many different sorts of toys you can provide. Budgies tend to like bright colors and do best when provided with a variety of toys that are swapped out on a regular basis when you deep clean their cage. Usually 2-3 toys in their cage at a time is enough.

You don’t need to spend a lot of money on toys for your bird; any toy will do as long as it’s made of bird-safe material and your bird can’t get stuck in it or hurt by sharp edges.
Budgies need foraging toys along with their regular toys to provide mental stimulation while they look for a treat.

You can make your own using tutorials like these:

sources:

"Wikihow- How to Take Care of a Parakeet" "VCAHospitals - Know your pet- Budgie feeding" "Zupreem - Toxic Foods Your Bird Should Never Eat" "Lafeber Company - Top Toys for Parakeets"