Speaking in tongues is also known as "Glossolalia." It's a fairly common occurrance, especially in African and Carribian animalistic religions. People get worked up into an emotional frenzy and start mumbling in syllables, and that's about it, really.
Some people enjoy it, and it unnerves others. And other folks regard it as silly. Try it if you think you might like it. But you should keep in mind that other religions have been speaking in tongues before the Christians ever started doing it.
Before you join a church --
Write down what your religious ideas are. Most churches have their own ideas of what's what, and before you can become a member, you have to say that what they teach is your opinion, also.
You might compare your ideas with the ideas (doctrines) of different churches, and then visit the ones you agree with, or like, the most.
Popular disagreements are found on --
1) Is Jesus human or divine or a combination of both?
2) Is there an actual Heaven and/or a Hell? Not everyone agrees.
3) Is the Bible 100% inerrant, without fault, and perfect?
4) Do women have to be subserviant to men?
5) Can a woman teach men in a church? Not all churches allow for this.
6) If a church member doesn't agree with all of its primary doctrines, can they kick you out? Some do.
7) Do you have to give 10% of your income to the church, or only what you can spare, or do you have to give both tithes (10%) along with offerings? Some churches have an annual congregational budget meeting, figure out how much they're going to spend over the next year, and ask for pledges from the members, which might be more or less than a tithe.
8) Does the church oppose war? Does it approve of it in some cases, or does it encourage war against a variety of heathens and infidels?
9) Is the Bible the only source of religious information, or does God expect people to use the brains He gave them as well?
There's lots of things you should decide now, before you go to a church, that is reasonable. If they say you have to pray 5 times a day, well, decide for yourself if that's reasonable for you. If you think it's ok for churches to require that you be supervised, or that you beleive everything that they tell you, well, fine. Decide that now, before you pick one.
Best wishes, and if you get into glossolalia like I did, make sure you carry a hanky for the initial learning phases.