I've been learning about trading on paper for a good year now...

I've been learning about trading on paper for a good year now and looking to finally take the leap and start trying it out.

I'm with Commonwealth bank and will be using Commsec to execute trades.
I've recently sold shares that I was holding on for over a year and realized that it takes 2-3 days to 'complete' or 'finalize' the trade even though the order got filled right away.



Assuming I start with a max of 10k, and today I perform a buy for 10k, and sell for 11k using CommSec,
How soon will that 11k be available for me to execute another buy? I would assume it is immediate if the order is filled?