Literally research a starting destination, and a hostel for the first few nights and buy the plane tickets. Investigate visa requirements of each country and look at ex-pat forums online.

Have a travel plan of places you want to experience, travel pla s can be flexible. Look at transport links. Explore the areas, hostels are a great place to meet people for excursions and to make travel arrangements. Get to know the areas, if you are staying more than a few days, book the hostel for one of two nights while you get to know the area so you can change if needed. Couchsurfing app is quite good. Enjoy local food and music events. See the local attractions and places you researched.

Make sure to have all your vaccination, visa and insurance sorted well before you go. Have a prepaid travel card such as revolut to exchange currency.

Travelling alone is great fun, you learn a lot, it can be scary at first but you soon realize that it is best thing you've ever done and you meet other people experiencing the same along the way. DM if you want to ask anything.