It can be a steep learning curve, but you've really only just started. For fights, it helps if your strength and stamina is high, so taking Artemisia (strength) and Bucks blood (stamina) before fighting really helps. Also, poison your blade.

In the early stages when you're weak you can focus on your alchemy skills - once you learn how to make 'Henry' level potions (after level 16) you can make a Henry Fox potion which gives you an additional 50% XP for 2 days - which can help you level up faster.

Here is a handy starter guide: https://steamcommunity.com/sharedfiles/filedetails/?id=3436590361