没错，take up 和 set up 都可以表示“开始”，但它们的用法有区别：

1. take up 表示“开始”，主要用于工作、职业、职责或兴趣、爱好等。如：

She has taken up a job as a teacher. 她当上教师了。

She takes up her duties / responsibilities next week. 她下周开始履行职责。

He left a job in the City to take up farming. 他辞去伦敦商业区的工作，开始务农。

He did not particularly want to take up a competitive sport. 他并不特别想从事竞技体育运动。

Angela used to be a model and has decided to take it up again. 安杰拉以前当过模特，现已决定重操旧业了。

2. set up 表示“开始”，主要表示建立、成立、创办等，表示从无到有的创建。如：

We are planning to set up a publishing house. 我们正打算建立一家出版社。

A working party has been set up to look into the problem. 已成立工作组调查该问题。

A fund will be set up for the dead men's families. 抚恤死难工人家属的基金会即将建立起来。

He set up a school for the blind (the deaf, the lame). 他为盲人（耳聋者，脚瘸者）创办了一所学校。

The government has set up a working party to look into the problem of drug abuse. 政府已成立工作组调查滥用毒品问题。

With Mr Ade taking the lead, they decided to set up a trading company. 以艾德先生为首他们决定成立一个贸易公司。