Welcome to Steemit @kayslab!

We all start as beginners so you are in good company. :c)

There is nothing wrong with writing in Korean (its just that English readers won't be able to access your thoughts as easily) so I'd suggest going with your gut.

I notice that some choose to write posts in two languages. This can be labour intensive - and so maybe a compromise would be a full first language exposition with a short summary in the second language). That is only a suggestion. :c)

It'll be interesting to see your thoughts on here. ^_^

Since you're new here, a quick read through this post may prove helpful.