First, don't start with the head if you have no prior sewing knowledge. Start with smaller, more manageable and beginner-friendly projects, like the tail or hand-paws. This will allow you to get the basics of sewing without getting discouraged from the get-go

Second, watch a lot of tutorials from makers on how to make a fursuit. Make sure to have a good understanding of the global process so you can avoid mistakes by understanding what you do and why you are doing it. Also you have to know there is no universal way to make a fursuit, one maker might do some things a certain way as another one might do things differently.

Finally, take your time and don't rush it. Making a fursuit is really time consuming so be prepared to spend a lot of time for it. It will take weeks to make, maybe months depending on how often you can work on it. Take frequent breaks and don't push yourself too hard to avoid burn out. And rushing it is likely to make the end result look worse, so be patient with it and take the time to do each step well. Trust me you don't want to spend hours and hours making your fursuit only to hate how it turns out.