The visitors lost the opening day-night encounter in Brisbane by an innings and 40 runs inside three days and followed it up by a 366-run thrashing on day four in second Test.
Sri Lanka have now lost a home series to England 3-0, then away to New Zealand 1-0 to go with their two defeats in Australia.
The first Test in South Africa starts on February 13, with the Sri Lanka squad flying straight from Australia this week to continue a tough overseas schedule.
"We are a young team and always learning how to play, especially in these tough conditions. We will bounce back in South Africa," Chandimal said
"I mean, they are three tough tours, we have finished two and now South Africa.
"South Africa is similar to these conditions and with very good bowlers. We know that as a team we have to play in tough conditions and we need to adjust to those conditions and step up as a team."
Sri Lanka came into the Canberra Test struck by injuries as they were without pace spearheads Lahiru Kumara, Dushmantha Chameera, and Nuwan Pradeep.
They were also missing the services of all-rounder Angelo Mathews, with the added off-field distraction of an ongoing ICC corruption investigation into Sri Lankan cricket.
While Sri Lanka have been transitioning in recent years, Chandimal said it was time for the players to grab the opportunity and start performing.
"If you get the chance to play for your country you have to take it with both hands," he said.
"Now as a team, we have to step up.
"In our young group, some of them have played more than 30 Tests so that means they are still very young, but in the international arena they are really experienced.
"So now this is the time to play your game and play for your team."
Asked to outline the positives Sri Lanka could take from the Australia series, Chandimal admitted there weren't many.
"The only positive was our slip catching from our fast bowlers," he said.
"I don't want to talk about the negatives," he added. "We all know what went wrong as a team and I'm sure the boys will learn from that and they will come good in South Africa."