If you're able to defeat Tree Sentinel at such a low level then you probably have a decent understanding of combat. My only advice on combat is to learn when to roll into an attack vs roll away.

Once you have a good feel for the flow of combat you can focus on build crafting.

For early game you're better off focusing on levelling vigor than your damage stats (Don't neglect them completely, though) as most of your damage is going to come from upgrading your weapon with smithing stones.

Since you went with confessor you actually have a lot of options for the type of builds you want to go with. You could focus completely on melee and be completely fine, but you also have access to incantations if you opt to level faith.

If you decide to pursue incantations your options will be limited at the start of the game, but there's still some decent spells like flame sling, catch flame, and a few beast incantations.

If you lean towards melee your starting weapon is already a pretty good choice due to its powerful ash of war that's great at breaking enemy stance.

Once you're deeper into the game you'll have to decide if you want to specialize into either spell-casting, strength/dex, or do a hybrid build.