I want to understand if I can use 做 instead of 当？
当 is grammarly correct, it means &quot;to be&quot;
当...（职业）is the correct expression. for example:
当老师，当医生，当科学家, and it cannot be replaced by 做.
做, means &quot;do&quot;, is to ask someone's occupation. for example:
你是做什么的？what you do for a living? it cannot be replaced by 当.
so 我一毕业就去上海”做“律师？ is a strange way to say but we also understand.
BTW, I think most of the problems asked in this Chinese Language section is simply because you guys don't have the context or not familiar with the convention.