can i be religious if i dont actually believe in any of it?

I don't know if it would help you...but I struggle with the same thing.. I think religion is fine, it helps people to become better, feel better e.g when they are guilty and desperate but personally I can't imagine that something divine created us people and the whole world. I believe that our existence is senseless, we just evolved.basically, we created ourselves. and no religion can make me believe otherwise.. i love the concepts of most of religions but at the same time they seem so unlogical, so unrealistic. 

edit: Btw, I wish you to find your way to God! try to talk to religious people about it, these typa conversations with them helped me to really seriously question god's/goddesses' existence at least for some time

Well, I think this depends a lot on definition and community. There are many traditions that either are religious or evolved out of religion that don't really care for divinity. Secular Buddhism is a thing for instance, despite the fact that, besides how some like to imagine Buddhism, it isn't really secular normally. 
Judaism also has in some instances parted with its religious roots and become more an identity and ethnic category,
There are also many who don't like the superstitious spirituality of some religions, but do like the philosophical spirituality.
These are just some things to think on.

Devout Catholic here,
Short answer is no, it would be insanity to fallow a religion and not believe it.
This can be solved though, you can start believing.
You are young and don't know much of Catholicism. While you may seem to find it unconvincing now, if you lean more of it, you may find otherwise.

If you are truly interested in becoming a Nun, you can visit them and learn more about what they do, how they live, etc. It would also be a good experience to meet people who devoted their entire lives to the Faith.

I also recommend just learning more about Catholicism from some good sources. There are great resources on the internet for all levels of knowledge and understanding. One type of talk that you might find very interesting are conversion stories. People giving testimonies of how they converted to Catholicism.

If you want to ask any questions, your free to ask me.
Also if you want to find some good Catholic videos and/or talks I can find some in the topic you need.