I'm sorry for the loss of your budgie. :hug.
You can definitely spend more time with the remaining budgie and over time he will learn to trust you more.
To build your budgie’s trust, sit by his cage and read, talk or sing quietly to him for a period of at least 10-15 minutes, 3 or 4 times day. After a few days, simply rest your hand on the outside of the cage when you talk to him so he'll learn that your hand is safe and will not hurt him.
The more time you spend interacting with him, the more he will learn to trust you.