Welcome to the world of wedding photography. If you understand the risks {mostly stated above} and you are confident to move forward this is the best advice I can give you.
Your friend’s wedding:
GET A CONTRACT – spell out every “what if” and have it in writing. Have your friend understand that this is your first time shooting a wedding and she should not have any expectations for results. Make sure you are on the same page and do not lead her to believe anything different. If she is let down you can almost guarantee your friendship will be over. It happens every day.
Looking at pinetrest is not going to help unless you know how to direct those people to do what you want. Remember this isn’t everyday life, people are drinking, have heightened emotions, possibly family drama and the only three people who actually care about the photos are you and the bride and groom {maybe the parents but they are going to be pulled every which way}. You need to know how to take control of a situation and also make good images while doing it.
Know how to use a flash, this is a Nov. wedding and it will be dark, dark, dark.
Make sure to bring backup gear. Camera body, lens, flashes, cards, batteries.
When you get home from the wedding, you are going to be OMG tired, your back and feet will hurt and all you want to do is melt in your bed or couch. Instead you need to upload the photos and back them up to an external HD or DVD immediately. Once they are backed up you can sleep.
Now for my advice on starting your businesses.
If you are serious, you need to apply for a Tax ID and a separate bank account for your business. Do this ASAP. Any money you make or spend goes through that account and you keep records of everything you make or spend. Self Employed are the #1 people to get audited and you could really screw yourself over if they find out you have been making money and not paying taxes on it. Put 1/3 aside of EVERYTHING you make to pay for taxes. You will most likely not end up owing anything the first few years if you are smart and put everything you make back into building your business {equipment, insurance, marketing}.
ALWAYS deliver on your promises. If you tell someone you will have their photos in two weeks have them done do it. Get back to clients promptly.
Always shoot. Everyday you make images you grow as an artist.
Find other photographers in your area, network with them and assist them.