This is gonna be a quick guide. Poppy is one of the under-appreciated champion like Gragas. As you already saw on the item build, this poppy is more hybrid than DPS Poppy or Full AP Poppy. It's really well rounded damage overall, and this champ is ultimate chaser with that hammer. Only reason I put Gunblade and Guinsoo's blade is so that i can utilize W, or Paragon of Darmacia and still get damages out of Hammer(Q) and charge(E). I usually take top lane.

As long as you harass the other player during the early game including watching out for the incoming jungle, you should be able to do fine.

and your ad's going to do a lot of damage during the mid-late game with decent attack speed with pens. I promise you.

However, if you are against going against Jax, make sure you are in the fight with the team.