Let's face it, learning a new language is hard. It involves perseverance, plenty of memorization, and a little bit of masochism, especially if you want to learn Japanese. Despite all of this it is also worthwhile investment in the long run, no matter why you decide to learn. The one thing to focus on is how you go about learning, because it is possible to learn the language on your own but you're going to have to be flexible on your definition of "learning the language." You can find the right resources you'll need online, for most of the services free of charge.
Know why you want to learn
Do you want to learn Japanese for business? To connect with family members? To simply play unlocalized video games? Whatever your reason, it's important to figure out why you want to learn so you can know what you need to learn. If simply speaking the language is good enough, find out what kind of resources are available that supply common phrases and pronunciation guides. If you want to read Japanese, start with familiarizing yourself with Kana, so you can at least be able to pronounce the writing. Also make sure you are learning the basics first, not rushing into using the language as you could make a mistake as you leanr and not realize it.
Set your expectations
As with all things in life, you get what you pay for. You're not going to be able to come out of this as fluent as if this was your native tounge all on your own. You'll be able to find plenty of information on certain basics of the language, but you'll be hard pressed to find out everything about the language.
It's also imprtant to note that trying to learn Japanese for free is good for people that are trying it as a hobby, or to be in pursuit of one. If you have a short amount of time to learn the language and it is very important that your learn, like for business, it would be in your best interest to pay for classes or software to focus your studies more.
Explore to find the best Resources
The internet was made to share information, so figuring out the best way to utilize its features would give you a definite boost in your learning experience. Flashcard websites that offer user created content can prove to an invaluable resource for those who don't like making flashcards. Plenty of websites exist solely to provide the basics on Japanese grammar with some ending up to be more helpful than others. Free softwares also exist that can provide a great help, but thye can be extremely hard to find. Joining a online forum could be helpful in order to seek out other good ways to learn for free. Even a simple google search can reveal some great resources. You just have to start searching!
Practice, practice, practice
Once you have found the resources best suited to help you, get to practicing. This is where you pour over flashcards, get to know what particles indicate what, and figure out how to ask where the bathroom is. A good way to get some practice is to watch Anime or read Manga, as it is readily available online and free. Just be warned that you might get confused, as Anime and Manga were meant for native speakers, so you might pick up some slang you could easily misuse due ot unfamiliarity. Always remember to double check your knowledge with a trusted and accurate source to avoid this kind of confusion.
Don't stress yourself
Remember: Learning Japanese is not going to be easy. Even those who have a propensity for foreign languages can have problems, so don't be so hard on yourself if you feel like you're not learning anything. If you can find a way to make the langauge fun, then it can become easier for you to learn.