There are a number of hiking trails in the Alishan area ranging from very easy to moderate difficulties. Overall great for beginner hikers.
Many well maintained and mapped trails and plenty of waterfalls.
No permit required.
Alishan Recreation area around the bus station has restaurants and hotels.
no guide needed
Alishan is a mountainous area in Taiwan famous due to its good infrastructure. You can easily go there by train and there is plenty of touristy infrastructure. Alishan is not one of the top 100 peaks of Taiwan, as it does not reach 3000 meters. That makes it a high point to reach with still a low risk of symptoms of altitude sickness.
Masses of tourists....