Hello It means 'I would be greatful if I stay next to you for the whole day of every day' or 'it would be nice to stay with you for the whole day of every day' 너 옆에 - 'next to you' or 'by your side' 하루종일- for a whole day 머무르면-if i stay 좋겠다- i would be happy/i would be greatfull/it would be nice Hope this helps^^