Need help with older & newer posts buttons

Hi everyone! ??

I’m designing a blog for someone here: https://test4.neshayasmin.com/

I’ve used the Novelty template here as a foundation for her design: https://themeforest.net/item/novelty-retina-ready-responsive-wordpress-theme/4367335

She wants two buttons at the end of the page, one saying ‘older posts’ and one saying ‘newer posts’.

The problem: the template I’ve used has numbers for each page instead of just two links going back a page or forward. I really need to change this to the two links.

If you have much html knowledge, I’d love your help!

Thanks,
N