Measure to include both IF statement and Concatenate

I am quite new to PowerBI and need some help writing  a measure.

Columns I want to work with for this measure are -

Client Job Number (multiple rows within each job number detailing steps completed in the job)

Start Date (multiple rows with start date against each step of the job)

Team Name (can do 1 or multiple jobs in a day)

Full Job Notes (a concatenated text column containing alphanumeric data).  

I want to write a measure that would be something like this.  IF "Team Name" completes multiple jobs "distinct Client Job Number" / "Start Date" then Concatenate "Full Job Notes" for all distinct jobs.  Blank if no jobs completed and if 1 job is completed then it would just be the "Full Job Notes".

How would I write this?

Thanks,

David