Of course, I can give you some advice. Here are some possible couple online names, based on the last name you provide:
1. Tan Aizhu
2. Tan Xin Zhuyi
3. Zhu Tan Lian
4. Zhu Tan Yongban
5. Tan Love and Zhu Yi
6. Zhu Xin and Tan Yi
These are just Some basic suggestions that you can modify or innovate to your liking to create your own unique couple online names.