If you are able to modify the destination table, you could make the default values for SessionID and TimeCreated do all the work for you. SessionID would be an auto-incremental integer while the default value for TimeCreated would be getdate() or gettime() depending on the data type.
Now, if you truly need it the values to be created as part of your workflow, you can use variables for each.
SessionID would be a package variable which is set by an Execute SQL Task. Just reference the variable in your result set and have your SQL determine the next number to use. There are potential concurrency issues with this, though.
TimeCreated is easily done by creating a Derived Column in your data flow based on the system variable StartTime.