Remove tags and author

In the CSS, in section 3, scroll down to /* Genericons */.

Then scroll down farther until you find:

.entry-meta .author a:before {
	content: "\f304";

Change to:

.entry-meta .author {
	display: none;

That removes the author name.

Next go to:

.tags-links span + a:before {
	content: "\f302";

Change to:

.tags-links {
	display: none;

That removes the tags.

Oh, one more thing:

These changes may be overwritten if the theme is updated. If you don’t want to have to repeat this if the changes are overwritten, then you need to create a child theme and modify the CSS there.

The advantage to that is you will always have the original CSS to duplicate if you make a mistake.