I don't really understand when to use each so generally I use the latter but I was wondering, is it ok to use the former with people you just met?
Generally, "я люблю" is just a stronger, more definite version of "мне нравится". When it is about things, foods, occupations etc., they are more or less interchangeable, e. g. both "Мне нравится запах напалма по утрам" and "Я люблю запах напалма по утрам" are OK, the former is more like just stating a fact, the latter is a bit stronger and more passionate.
When it comes to people and relationship, it's basically same as above, but with the additional nuance of being permanent and exclusive. For example, "Мне нравятся Катя, Маша и Таня." (e.g. I kinda like all three of them somewhat) vs. "Я люблю Таню." (e.g. she is the one, it's more like the confession of love, not to be used lightly). "Я люблю" also usually bears sexual (and/or matrimonial) implications, if you want to use something strong but without those, you could say "Я обожаю ..." Obviously, a lot depends on the context as well.
If a native speaker says "I love you" to a person he just met, that person would probably be a little scared. However, the perception may vary between different sub-cultural groups.
Basically, you should distinguish the phrases 'I like/love smth in general' from 'I like/love this particular thing'. As @Headcrab said, "люблю" denotes a settled and durable feeling, while "нравится" can refer to both deep and superficial feelings.
I like/love flowers [in general]. -- Мне нравятся цветы / Я люблю цветы.
I like/love this kind of flowers -- Мне нравятся такие цветы / Я люблю такие цветы.
I like/love these [particular] flowers -- Мне нравятся эти цветы only. Я люблю эти цветы would imply that this specific bunch of flowers has been standing there for a long time, with the speaker admiring it every now and then and probably falling in love with it :)
The same applies to the common English phrase 'I love it!' ("Мне нравится!" only).
Therefore, using "люблю" with a first-time acquaintance should definitely be avoided.
With verbs, both words can be used:
I like/love to travel. -- Я люблю путешествовать / Мне нравится путешествовать.
However, keep in mind that 'would like/love to' would usually be translated using want and enjoy:
I would like to travel. -- Я хотел бы отправиться в путешествие.
I would love to travel. -- Я бы с удовольствием отправился в путешествие.