is there a way that i can pull all scalars at once?

I guess you mean from multiple Tasks ? (if so then the answer is no, this is on a per Task basis)

Or, can i get experiments list and pull the data?

Yes, you can use Task.get_tasks to get a list of task objects, then iterate over them. Would that work for you?
https://clear.ml/docs/latest/docs/references/sdk/task/#taskget_tasks