You can upload your logo image in the Theme Options. If the logo is not uploaded, then your site name will be used.
Please, follow the steps below to upload your logo:
Step 1 : Log into your WordPress Dashboard and navigate to Theme Options > General Settings > Upload Logo .
Step 2 : Upload a Logo ( Logo used by most of the devices including desktops and not retina devices ) or a Retina logo ( Retina Display is a marketing term developed by Apple to refer to devices and monitors that have a resolution and pixel density so high ). Size doesn’t matter but if you want to make logo retina use a bigger size ( roughly 300 or more pixels per inch ).
Step 3 : If a retina logo is used, you may want to adjust the width (164px) or height (45px) options provided.
Step 4 : To Upload your favicon, navigate to Theme Options > General Options > Custom favicon . Your favicon should be a 32px x 32px Png/Gif image.