If you want to express the order of three actions, you have to state 再 or 又 before the second action.
We use 再 when we are talking about regular actions or actions in the future, and we use 又 if we are talking about actions in the past.
On this trip we firstly went to Beijing, secondly to Xi'an and lastly to Nanjing
zhè cì lǚxíng wǒmen xiān qù le běijīng, yòu qù le xī'ān, ránhòu qù le nánjīng
I get up at six every day, brush my teeth, then exercise, then eat breakfast