I'm also a beginner with no fight experience but your question is important for me as well as a lot of the people I did sparring with so far were quite punch-focused (and I am not).
2 Things that seem to put a break on a punchers advance (at least on those that are not leaps and bounds ahead of my skill anyways of course) for me are:
1. Long guard and keeping a hand towards their face to interfere, disrupt, annoy. The better one's tend to get around it sooner or later but I guess with more experience it can at least help. I am quite tall though so if you are a smaller build this might not work as well for you.
2. Quick inside leg kicks as they step forward to punch. This proved quite effective as far as my skills will allow. It unbalances them and makes them more vary to step in again. Also the pain starts racking up over time if you can sneak it in more often. Good footwork can of course only make it better. I've also seen this approach used to sweep people clean off their feet as they try to advance with punches (look at Karuhat for a technically godlike example)
Teeps seem to work, too but I'm not yet good enough with them to stay out of trouble while using them. Need to improve my timing and power I guess.
