...rather than ask how, ask WHY you want to be in wedding photography. Is it to try to make an expensive hobby pay? Is it to actually be a pro wedding photographer and compete with the big folks?
Once you answer that question (even more importantly, if you CAN'T answer the question), you'll know what to do.
If you want to be a pro, then join local photography organizations, get some training at a real studio, assist some weddings, start shooting on your own at pro prices so you can cover the cost of your training and massive amounts of equipment.
If you want to just make your hobby pay, do weddings for friends for a few hundred dollars and be aware that their expectations and your results may not match, and be prepared for the relationship changes that result from that disconnect. Better yet, shoot landscapes and sell them as calendars and prints, don't do weddings.
I don't want to sound harsh but weddings are not to be photographed lightly, not to be photographed with amateur equipment, not to be photographed without backup equipment. I have $10,000 to $15,000 in digital camera equipment and software to process my pro weddings and I'm on the smaller investment size compared to many other photographers. Are you wanting this avenue of income and expense?