Going to Tivoli

Asked and answered
https://community.ricksteves.com/travel-forum/italy/the-best-way-to-go-from-rome-termini-to-tivoli

Good answer. But without knowing whether you are going to one or both major Tivoli attractions, month of year, mobility restrictions, budget, return to Rome or not, the "best" answer is uncertain.

Here's a more complete list of posts from the past year regarding Tivoli - just ignore the responses related to Denmark:

https://search.ricksteves.com/?button=&date_range=1y&filter=Travel+Forum&query=Tivoli&utf8=%E2%9C%93