Bahasa means language, Indonesian speaks Bahasa Indonesia, but westerners say Indonesian speak Bahasa. That's wrong :)
Bahasa Indonesia is simple. There is no present and past tense, there is no masculine or feminine words.
The structure of Bahasa Indonesia is similar to English:
Subject + Predicate + Object + Place/Time
We can also put Place/Time before the Subject.
These are the list of important words that we usually use as subjects:
Saya, Aku : I
Kamu : You
Kalian : You (for more than one people)
Dia : He/She
Mereka : They
So let's try:
Tadi malam saya makan nasi goreng di restoran.
Tadi malam : last night
Di restoran: at a restaurant.
You should be able to understand the whole sentences ...