It sounds like you've been doing some homework on fasting and have no doubt started a new fast. Although you have limited experience, you really have nothing to worry about at this stage but it will be wise to keep us up to date with your progress and any concerns that crop up.
Although it's early stages, have you already decided on a refeeding plan? If not, this is a good time to read up on how to break the fast, whether at 3 days or 30 and have a plan in mind of how you'll accomplish this. Unless you have great will power, the temptation to overeat will be great but after the 5th day or so, the digestive system will have shut down and will need gently waking up. Apologies if I'm teaching you to suck eggs but too often this all important phase gets left til late in the day.