How do you say

I’d like to book a ticket three months in advance, please.

..in Chinese?

我要预定一张三个月后的火车票。

wǒ yào yù dìng yī zhāng sān gè yuè hòu de huǒ chē piào 。

How do you say "He works out every day, with the goal of improving his health over the next three months." in Chinese?