someone talk me through increasing website traffic?

if it's never really been there, the quickest wins are usually pages that already get impressions but sit on page two. improve those first - fuller answer, clearer title, a couple of internal links pointing at them - before you write anything new. new content takes months to settle, nudging position 12 up to 6 can take weeks.

Before touching anything - is the traffic flat, or did it fall off a cliff at some point? Those are two different jobs and the graph in Search Console tells you in about a minute. If it fell, you are looking for what changed: a migration, a redesign, pages dropping out of the index. If it was never there, it is a coverage and content problem and no amount of tinkering with title tags fixes that. What does the last sixteen months look like?