Good think you already know English. You may try some basic grammar sites for English-speakers. Try in Google or YouTube with "spanish grammar" "spanish lessons", etc.
Then try reading online SP (formal) newspapers, or using the forums here. Keep in mind that most people here aren't formal teachers, though they are also learning languages, so they'll be kind and patient with your mistakes, something much appreciated by beginners like us.
I suggest leaving real-time conversations (chat/skype) for last stages, or once you feel yourself enough fluent and confident in talking.
Anyway, the point is that this thing is made of people learning and making mistakes all the time, in all languages. So feel free to join teh forums and learning groups here.