So I've been thinking about a few things about my birds lately.
My first two budgies are kind of old, about to be 8 years, and I'm worried that when one of them pass and the other will be depressed and lonely. I have two other female birds in a different room because I'm working with them on trust and taming. IF/when one of my older untamed birds pass what should I do for the other? Hes not tame and I'm worried that if I place him with the females that it will cause trouble like fighting or he might effect the taming as he is not tamed. I don't think I should leave him in his large cage alone, but I don't want to move him to the smaller travel cage I have. What should I plan on doing when that time comes? I want to be prepared.
I think its about time to give my two newest budgies a vet visit. I'm not sure how to get them into the transport cage or what to really expect. They are doing really good with taming but are not fully there yet with hands and really anything without millet. How should I proceed to getting them a vet check up?
It's not a good idea to mix budgies of different sexes when there's an uneven number. It can cause fights, sometimes even to the death.
In my opinion, the best course of action would be to start taming your older two budgies, at least to the point where they are hand comfortable with you and comfortable with your presence. Yes, older budgies can get used to/tame with humans. Obviously it's no guarantee, but it's definitely worth a try.
For going to the vet, a lot of people like the hand cloth method. That is, pick up the budgies with a cloth covering your hand so they don't associate your hand with grabbing. You can practice picking up other small objects to get comfortable and then try it on your budgies.
Is it an avian specific vet?
See if you can go to a proper avian vet. A lot of regular vets don't actually know or recognize bird illnesses and sometimes have no more training than a textbook chapter from way back in vet school. An avian vet will know how to properly deal with birds in all ways.
In regards to training, I personally like the clicker method.
When one of your untamed birds passes, I would NOT move the other into a different cage.
Many older budgies will adjust well to being solo birds and there is no reason to disrupt the bird when it's recovering from the loss of its friend. I'm assuming both of these birds are male as you indicate "He" will be alone. (?)
The budgie(s) are about 8 years old according to what you posted so allowing the bird to enjoy its senior years alone is going to be your best option. You will need to spend time with the bird on a regular and consistent basis every day so it isn't lonely.
Be sure to play music for it when you aren't around.
With regard to taking your budgie to the vet:
Avian Vets have special training to determine the cause of symptoms resulting from illness or trauma.
This is important as "regular" vets will often overlook symptoms that are quickly obvious to an Avian Vet.
When you rely on anyone who has not had training in Avian diagnosis and care, you may be delaying effective treatment.
This can prolong suffering that may be avoidable.
The bird will often require a more intense, prolonged treatment with a poorer chance of full recovery than it would have if you seek prompt professional diagnosis and treatment at the first sign of illness.
If there are no Avian Vets near you, please find an Exotic Pet Veterinarian with experience in dealing with small birds.