Congratulations! This is big news!
It's possibly also a little overwhelming! Once the surprise wears off (if there was one!) then the questions hit. "Where do I start from here?" "Now what?" This is completely normal, even if you've been married or engaged before.
We've got some tips to help you get started. Also, there are great resources out there to help you as well, and most of them are free!
Tell your family and friends! They can help as well, with planning or scheduling appointments and showers.
Discuss your visions. Talk with your significant other about what each of your visions for the wedding looks like. You can decide what are "Must Haves" and what aren't and know what direction your planning will take.
Decide if you are a planner-type person or a non-planner-type person. This will help you to decide if you need to hire a planner to take care of all the details. If you do hire a planner, that leaves more time for you to just enjoy your engagement and take it all in. Some people thrive on the planning process, and if this is you, that's ok, too! For some people, control over everything is calming, as you know exactly what is going on, and you know that it will be what YOU want.
Get organized. Set aside some time to relax and think about what you want your day to look like. Begin to organize all of your information. Whether it's a binder or an online scrapbook, maybe a Trello workspace with boards and cards, or Pinterest with photos linked to websites and articles. Whatever way you are best at organizing, now's the time to start. Even if your wedding is a year or more in the future, planning now can make sure that any obstacles that come up have time to be solved and fixed. Websites like The Knot have wedding planning tools and apps that might make things easier for self-planners.
Create your budget. Decide your total amount to spend, and divide this total into categories, such as Decorating, The Dress, Tux Rentals, Honeymoon, etc. You may even want to set aside a little extra for surprise expenses that you hadn't thought of.
Start a checklist. You'll want to create a list of tasks to help you through the planning. To-dos can be broken down into month-by-month tasks, which may help in relieving the stress of planning so many details.
Delegate. Is your fiance going to help plan the wedding? What about your parents or your fiance's parents or family? If you have people who will be helping with planning tasks, make a list of their delegated tasks and get them started.
Once you have gotten this first step taken and have something of a plan started in a physical form, you are ready to start the real work towards creating the perfect big day.