Initially start with close by place, plan your trip thoroughly, your stay and mode of transport are 2 main things which are important for your safety so be thoughtful of that and go through the reviews and check the location of the stay beforehand. After some trips you'll get the hang of it and will
I started solo travelling 3 years back and i love it. Try to gather as much information as you can about that place.. places to cover, famous cafes, most importantly your stay (hostels, my preference), basically anything that interests you. Pre-book and just GO!!
It's natural to be anxious and fearful at first, but initially it will help if you have a proper plan in place. Your mode of transport and your stay is very important for safety reasons and that decides the people that will surround you so be thoughtful of that and check the place out and reviews too before you get into something. After some time you'll get the hang of it and will feel more free travelling around alone even without a plan.