im in need of help. im new to this program and i just finished my drawing. exited over it i wanted to make it my laptop wallpaper, but i need to have it as a picture. please help me save it as a picture. thank you

Go to the fIle menu, select "save as". In the file dialog select a suitable image format: jpg, bmp or png. Save in that format. Now you should be able to use the image as a wallpaper. Check https://userbase.kde.org/Krita/Manual/TopMenu/File for more information.