No.
There are any number of enlightened beings (Buddhas) in the world. The Dalai Lama, for example is held to be the reincarnation of the Buddha of Compassion.
If the question is "How old do you have to be to become a Buddhist?", there is no age limit. Like Christians, Buddhists can be born into Buddhist families and be Buddhist from birth. Conversion to Buddhism from other faiths can occur at any age. If the questions is"How old do you have to be to become enlightened (become a Buddha)?", there is no age limit. The Dalai Lama is considered to be the reincarnation of the Buddha of Compassion, as a consequence he would be a Buddha and enlightened from before his birth.
Only Tibetan Buddhists do... the Dalai Lame
Buddha, also known as Siddhartha Gautama, was the founder of Buddhism in the 5th century BCE, while the Dalai Lama is a title given to the spiritual leader of Tibetan Buddhism, believed to be an incarnation of Avalokiteshvara, the Bodhisattva of compassion. The Dalai Lama's teachings are rooted in the principles established by Buddha, and he serves as a prominent figure in the dissemination of Buddhist philosophy and practice. Although they lived in different times, the Dalai Lama's role is to continue and uphold the teachings of Buddha, adapting them to contemporary contexts in Tibetan culture and beyond.
999 Dalai Lamas are there
He is both the spiritual leader of Tibetan Buddhism as well as the political leader of Tibet. He is considered by Tibetan Buddhists to be the fourteenth incarnation of the boddhisattva Avalokitesvara, the buddha of compassion. He is continuously reborn with the goal of ending the suffering of all sentient beings by helping them all to reach nirvana.he bringss peace
The Dalai Lama is the spiritual and political leader of Tibet. Tibetan Buddhists have a system of recognizing lamas who have been reincarnated, such as the Dalai Lama. These are called Tulkus or Rimpoches, and they are recognized as having spiritual acumen. Lamas are recognized as having the spiritual authority to teach others. Monks can be lamas and/or rimpoches, and they enjoy respect and authority from lay people.
Buddhists.
Yes
The Buddha is an historical figure that initiated Buddhist practices and philosophy. The Dalai Lama is believed by his devotees to be the reincarnation of a long line of tulkus who are considered to be manifestations of the Bodhisattva of compassion, Avalokiteśvara.
The Dalai Lama's goal is to bring peace, gratitude and compassion to the world.
I have attended meetings addressed by the Dalai Lama. Buddhists seem to invariably treat him with the greatest respect, and hang on his every word. Those who can touch his hand feel blessed.