Dw i wedi blino heno ~ I am tired this evening.
Draig dw i ~ I am a dragon.
Why does the word order change?
The default word order is verb + subject + other stuff (including object).
The 'usual' word order is verb-subject-object (VSO), but this is subject to frequent exceptions due to emphasis - whatever is being emphasised is usually placed at the beginning of the sentence.
There isn't a true object with those, but the point is that the emphatic construction is usual in those patterns, with the verb coming second in the sentence.
I would use the word 'Archebu' to order. Or you can use 'gorchymyn'. Yes word orders are very different from English and similar to latin based languages like french, Spanish.