Hello, Hoang!
Unfortunately, you can currently have either text or Logo, not both at the same time.
There’s a workaround if you want to try…
To have the Logo before the Site title, leave the Site title, then add the following code into Customizing->General->Additional CSS:
.site-title a::before{
display: inline-block;
margin:15px;
width: 110px;
height: 110px;
vertical-align:-50%;
content: "";
background: url(https://secure.gravatar.com/avatar/a97d62aaa58572c17d9c1c6bb0e5905f?s=80&r=g) no-repeat 0 0;
background-size: 100%;
}
Change the background URL address, height and width values per your needs.
Regards