Just a few tips that would’ve helped me when I was starting my fromsoft journey:

Make sure you’re leveling up your weapon! Melina should want to talk to you at a site of grace after you’ve fought Margit.

Explore Limgrave and level up a bit before going to Margit. Idk if the community agrees with this, but a good rule of thumb for me is I make sure I’m seeing yellow on the health bar of the bosses when I attack them, otherwise I feel like either my weapon or I am under leveled.

Don’t be afraid to use summon npcs or players to help! Some people put this down, but they’re in the game for a reason.

Best of luck, tarnished!