Hi,

1/ To change the size of title on the featured slider style 2, please add more this code to Customize > Custom CSS:

\
.penci-featured-content .feat-text h3 a{ font-size: 28px; }

Change number 28 to value you want.

2/ I see you did changed this code from style.css of this theme to 1500px:

\
.featured-style-2 .penci-owl-carousel .owl-item .item{ width: 1500px; }

by default, this has width is 900px

If you want to change it, please add more this code to Customize > Custom CSS:

\
.featured-style-2 .penci-owl-carousel .owl-item .item{ width: 750px; }

Change number 750 to value you want.

Best Regards,

PenciDesign