What would you do if you met the actual Norse god Loki and he asked you to help him but he wasn't anything like Tom H. but very very ugly?

I'd help him anyway.

If he's showing up as an ugly person, then he's doing it on purpose for a reason, since the actual Norse god was described as being attractive.

Beyond that, I don't decide on whether I help people or not based on how suitable their face is.

Bri-marie is right. Loki can look however he chooses. He's a skilled shapeshifter.
If he did ask me to help while wearing his ugly disguise, well, it depends. If he just walked up without introducing himself or anything and said, "I need your help," I'd probably have some snarky reply implying that he was a creeper. If he walked up and told me he was Loki and needed my help... I probably wouldn't believe him. For several reasons. But if he proved it... It wouldn't matter how he looked. He could consider me recruited.

It's still Loki, why should I just care for his looks? Though in Norse Mythology it's said Loki is the most handsome of men <3

It's said in the prose of edda that loki (the trickster) could charm the leaves off a willow tree and was quite a looker, yet he was also delicate with a supremely inteligent mind and mastery over magick. he could shape shift into anyone or anything. I don't think that the real loki looks anything like tom, but that would be just fine with me.

I'd ask what he wanted me to help him with. I'm not just going to do a favour for someone if I don't know what the favour is.
Depends, exactly.