First of all, Jun "くん" is usually a title for the younger generation, peers and subordinates, such as Jun Yamamoto and Jun Suzuki. Although surnames are usually added before Jun, sometimes in order to distinguish them from people with the same surname, names are also put before Jun. For example, Masahei Yamamoto will be called Zhengping Jun. In addition, it should be noted that in companies and other workplaces, "Jun" is not limited to men, and superiors often use "Jun" to address women at lower levels.
At that time, the title ちゃん was a nickname for the younger generation, peers and women. Sometimes, because of their intimate relationship, ちゃん can also be used to address men, but it should be noted that ちゃん is preceded by a short pronunciation of the called person's name.
As for the temple "どの", it is a kind of written language, which is usually used for writing and letters. It is usually called the top managers, celebrities and people they respect of the other company. Never use it in daily conversation, others will think you are an ancient person.
The above contents have been explained. I don't think it is necessary to explain "さん" any more. As the experts on the third floor said, anyone can use it, except themselves.