Is it “bad” to want a “materialistic” happiness?

Am I not allowed to dance? To sing? To fall in love?

You allowed, because a lay man just has to observe 5 precepts, first. However, how you sing is how you unpracticed in buddhist training. So, to understand buddhist teaching deeper, a lay man may observe 8 precepts 1 day per week. This 8 precepts included watching/dancing-rejection, listening/singing-rejection, and making-love.

Is the purpose of Buddhism to become a munk or nun? To meditate and never get a taste of life?

No, buddhism purpose to enlighten nibbāna, both lay man and ordained man can meditate to enlighten nibbāna. But the ordained man is expedient to do, because of their discipline life-style. Similitude, you can learn in the university, and you can learn by yourself.

Is it "bad" to want to travel?

The buddha just cared the traveler about the risk between the travelling, see S.N. Nidānavagga Duggatasutta. Both this life travelling and the other lives travelling are very risk.
The monk still travels to search for a good place for the meditation. He happy with his life. But the monk's travelling leading to finish the cycle of traveling (dependent origination), so it is not very risk when compare to the general travelling.

Is it "bad" to want to be happy and/or content?

It is risk to happy with 5 kāmaguṇa, 5 strings tied you to 5 kāmaguna, see M.N. Mūlapaṇṇāsaka,mahādukkhakkhandhasutta.

Is Buddhism about finding happiness in Nirvana? Is that really it? Is it not about being happy where we currently are? Are we not allowed to truly live in the moment?

We can be happy with every state of life. But nibbāna is the best happiness which give the best resultant. So, no one can force you to happy with your life, but don't be sorry later, when you knew "Oh, I this happiness come with the problem, suffering" like we daily doing in M.N. Mūlapaṇṇāsaka, mahādukkhakkhandhasutta.

I am quite new to everything about Buddhism, and I apologize if anything I've said in this question is insulting or rude. I don't know who else I can ask questions like these. I hope someone can explain to me.

Your question is not insulting or rude. You just confuse about the benefit/ the advantage of the buddhism, because dhamma of buddhism is the hardest teaching to understand and to follow in few years. But do you know? Hard working causes the best benefit.
Someone used his whole life to train follow to the buddha's teaching, but in the end of life he still not enlighten nibbāna. This is how the buddhism's teaching hard.