Hi,
Try to gain experience on Customer Service module - which will go good with SD. Also, on top of it you can learn - Transportation Management.
Next, you can explore the option of learning CRM module wherein we can nurture the learning along with SAP as its an evolving module. With in CRM you have sub modules like : CRM Sales, CRM Service & CRM Marketing. In which CRM - Sales would go better with SAP SD.
Of all, the preference priority would be first - Transportation Management, next - Customer Service, Next - CRM (Sales).
Please let me know for any specific query.
Regards
