No worries, have you seen the shared folder that Zev's author set up? Ronin's character sheet is in there, as well as a started document like we did with Kir's post. If you didn't get the share check in with Zev.
As for making an attack against one of the goblins, you simply need to select your target, then select your weapon (rapier or dagger in melee, or shortbow if you'd like to stay at a bit of distance. Either way your attack bonus is +5, so you roll your 20 sided die (d20) and add 5 to the result. If the total is 13 or higher, their armor class (AC), then you've connected with your attack.
If you get 12 or less, you've missed and that's it for your turn. 13 or higher means you've hit and need to see how much damage you've done. This is where the other dice come in, if you used the dagger you roll your four sided die (d4). The rapier uses the eight sided die (d8), and the shortbow uses a six sided die (d6). You'll add 3 to which ever die you rolled and that is the total number of hit points (hp) that your target loses. The goblins each only have six, so if get more than that, you've stopped him in his tracks.