We write to get a message across, and we must ensure our message is clear. So, yes! Spelling, grammar, and punctuation are important, and can be dealt with given time and patience.
What is the ideal word count?
One needs to consider whether 37 words are necessary when 5 could be thought adequate. It all comes down to 'What are you actually trying to say'?
Consider the writing which you enjoy reading. This may give you direction as to where you feel comfortable taking the early steps in your creative writing.