Well, if you're gonna use it in your party, probably the best moves it learns as a Snorunt are Ice Fang and Crunch. Both moves can be learnt at Level 28/31, respectively. It can't learn those moves as a Froslass, but Snorunt also learns Blizzard at Level 46, five levels lower than Froslass, so you can take that into account if you want.
Snorunt and Froslass have generally the same moveset TM wise as well, so I wouldn't worry about that. If you wanna look more into Snorunt and Froslass's moves, click here and here.
If you aren't going to use it in your party though, I guess you should just evolve it as soon as possible. xD
Hope I helped. :)
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