After the opening cinematic, you will be asked to name as well as design the appearance of your character. The most crucial of these options is "Class", where you get to pick the one that best fits your play-style. I personally went with the Knight because of their defense, which hopefully translates to better durability. For "Burial Gifts" I went for the Life Ring but you can of course pick whichever one you like best. Finish off the rest of the character creation process to start with the game proper.
This is essentially a tutorial level which aims to get you acquainted with the controls. If you've played previous Dark Souls games the controls should feel familiar and be easier to get used to. Head down the path where you'll be greeted by a Hollow on either side. They can can do some damage despite the shabby sword so wait for then to take a swing at you so you can dodge or block that before countering. There is an Ashen Estus Flask down the west path. At this point, feel free to explore and just look around while getting used to battling Hollows. I noticed too that the drop rate for this game is quite a bit higher than in the previous Souls titles, so taking the time to kill enemies is good.
Continue through the main path when you're done checking things out. Light the bonfire that you see here and rest. Take note that while resting fully revitalizes youur character (and replenishes your Estus Flasks), it will also revive all the enemies that you've defeated. You'll get a trophy/achievement Enkindle for lighting the bonfire by the way.Make your way towards the big building and past all the enemies to a clearing where the very first boss of the game awaits. Pull the sword out to start the battle.
Boss Battle - Iudex Gundyr
Iudex Gundyr has a fairly long reach as his weapon obviously suggests. But thankfully the attacks from it can be blocked. As always the evade/block and counter tactic works well here. Defend until you block his attack then move in to counter. Strafing as you attack also works so you are constantly a moving target. Once you've dealt enough damage, the boss transforms into this grotesque-looking monster. Don't let yourself be intimidated by this and continue with what you've been doing thus far to finish the battle. Use those Estus Flasks if you need to as well.
You'll get the Coiled Sword for defeating him, along with the Iudex Gundyr trophy. Light the bonfire here next to unlock the Embrace the Flame trophy.
Moving on after you've muscled the big door open, check the corpse by the headstone to get a Broken Straight Sword. Proceed to the ledge and head left to alcove along the pathway to the Firelink Shrine. You'll find a pair of enemies protecting an item behind them. Kill these guys to collect the Homeward Bone. After which you can continue onward to the shrine. Keep an eye out for more enemies on the way though.