Hi, as you already know it's too late to try to catch up now. Don't overdo it till race day and maybe you want to consider doing a walk/run strategy for the race. If this is your first HM I wouldn't stress about the finishing time and just aim to finish and enjoy the experience. Good luck!
Hi Dave. Good on you for starting to run. As already advised get some comfortable running shoes( not the ones the sales person thinks you should buy. If they are not comfortable don't buy them). Look at the C25k program and find your nearest park run which is fantastic way to get into running and no one will judge you if you walk it. Oh and talking about judging, being embarrassed when out running... Please don't care what other ppl might think. Most won't notice you anyway and the rest couldn't care less what you do, so get out there and enjoy it