How do you say

I've made plane reservations online, and I'm flying to Beijing at the beginning of next month.

..in Chinese?

我在网上预定了机票,下个月初就要出发去北京了。

wǒ zài wǎng shàng yù dìng le jī piào , xià gè yuè chū jiù yào chū fā qù běi jīng le 。

How do you say "Three months later, he called us ‘Mum’ and ‘Dad’ for the first time, and it melted our hearts." in Chinese?