To split Text Block into 2 Columns, you can follow these steps.
#1. First, find Text Block ID
In my example, we have: #block-yui_3_17_2_1_1730016779381_9244

#2. Next, use this code to Custom CSS box
div#block-yui_3_17_2_1_1730016779381_9244 {
.sqs-html-content {
display: grid;
grid-template-columns: repeat(2,1fr);
grid-gap: 5px 5px;
}
p {
margin-top: 0px;
}
}

#3. If you want to make this run on Desktop Only, use this new code
@media screen and (min-width:768px) {
div#block-yui_3_17_2_1_1730016779381_9244 {
.sqs-html-content {
display: grid;
grid-template-columns: repeat(2,1fr);
grid-gap: 5px 5px;
}
p {
margin-top: 0px;
}
}}
