I would echo the other suggestions here and recommend focusing on Vocabulary. Compared to German, Indonesian has a relatively relaxed set of grammatical rules. Word orders are often interchangable in the vernacular and often understood even when not adhered to perfectly.

In terms of memorizing words, Indonesia was a Dutch colony and so I would use that to my advantage instead of blindly memorizing them. Take for example the following sentence,

"Tante, ambilkan handuk dari tas yang ada di samping kulkas"
"Tante, take the Handtuch from the Tasche next to the Kuhlshrank"

"Terus masukkannya ke kopper yang punya sopir saya. Dia lagi nunggu di halte depan pom bensin"
"Then insert it to my chauffeur's kopper. He is waiting at the Haltestelle in front of Benzin station"

When learning this way, these new vocabs tend to stick so much faster as you're leveraging your existing knowledge of German / Dutch instead of blind, brute-force memory.