To provide your Japanese proficiency with a certificate for your future job opportunities, you can take JLPT.
JLPT(日本語能力試験 The Japanese-Language Proficiency Test), is a standardized Japanese language exam to certify Japanese language proficiency for non-native speakers. It covers language knowledge, reading ability, and listening ability. The test is held twice a year in Japan and selected countries (on the first Sunday of July and December), and once a year in other regions (on the first Sunday of December).
Unfortunately, December 2020 JLPT – Cancelled In Sydney and Melbourne. However, Adelaide, Brisbane and Perth - confirmed so far (15/8/2020). Please check the detail in the following page.
You can try sample questions on the official website and check your current Japanese level.