how can I fill the grey bars behind the language in my profile?

it's so annoying to see them all grey there. do I need to take language tests on the website or something like assessment?

Remember when you signed up and they asked you what language you speak and how well you speak them. This is just a graphic representation of that. You said you are still a beginner, that is why you see all the grey. You can adjust it by editing your profile by saying your English is advanced.