What are you feeding your new pal? Tiels should not be fed a diet entirely of seed. My tiels get a one Nutriberry a day in the morning with Harrisons pellets and Harrisons and 1 tsp in the evening. Some people give less millet and more pellets. Don't feed one of those cheap generic seed brands from supermarkets or pet stores. Many years ago I did feed Lafebers pellets. It is OK food, in my opinion. The vet wanted us to change, so we did. Anyway, ask people here what they feed and you'll get an idea of what to feed your pal.
You do need to strike the right balance between millet, pellet, or whatever you feed for seed. Believe it or not, you can do liver damage if your bird does not get enough seed or nutrition in general. Fortunately, you have come across a wealth of information on this board. There are many knowledgeable people who can advise you on diet and other things to make your bird's life better. I've had tiels 14-15 yrs. Some people have had them much longer.
Please do ask others what toys are good. Some toys the pet stores sell are not good and plain dangerous. I hang toys off the sides of my cages, near the bottom of the cage. If a bird gets caught up in it - at least they can get their footing to get out. Snuggles likes to chew newspaper and anything papery. Be careful of toys with parts your bird could choke on.
I am not sure I agree with him, but my vet thinks our new tiel lost all his primary feathers by getting caught in a toy and flailing around during the night. Maybe he is right, but that toy is gone. He came to us with that toy when we adopted him, but no matter. It's gone. Look at a toy and ask yourself, could this hurt my bird in *any* way?
Snuggles once got his foot tangled in some ribbon like straw material commonly sold, but I was right there to help him. I chucked the rest of that ribbon. If you happen to buy one of those little stainless steel tiny dome type toys where you put something in it for the bird to pull out, put shredded newspaper in there, or you could buy some colorful shredded paper to put in there. You could also put millet in there for a foraging activity. Birds like to work for their food. It's fun for them.
It's important to give them something fun to do, or they could develop unwanted behaviors.
Sorry for the long post. I want to prevent you from making mistakes I did. Thank God, I never lost any bird to an accident with a toy.