Hi there,
It´s always a thing traveling in and out of Canada while having applications in process
So... I understand you are in Canada, right ? So you´re pretty new here, and that´s an advantage, you´ve just been 3 weeks, so going in and out has to be completely ok. The thing is that if you apply for PR from within Canada, that is Inland, it has the advantage that yoiu can also apply for a Work Permit at the same time, but it´s expected that you remain in Canada during the process. If you apply Outland, you can still be in Canada, and you can travel, the only thing is you cannot apply for a Work Permit. But I read for people from the US applying Outland is pretty fast, and most people do that. so mayb in your case it´s more convenient. But in any case, since you have to wait for your marriage certificate to apply, and it takes about 2 months to arrive, you can travel to Ireland first, and then apply for PR, after your trip. And that is completely fine because you are just visiting Canada with your husband. But I syill think Outlnad is best in your case.
Hope it helps