Hi jovanean! thats a good question. Since Poppy has a weak early game, i suggest to play it safe and farm under tower for the time being. i also suggest you to buy ninja tabi's and a thornmails to negate her damage. once you reach lvl 6, try to pressure her ever so often so that she will back off little by little. when trading, try to bait out her parry so you can successfully use E to stun her to a wall, or using ulti to engage to try to get into a suitable position to use your combo. Fiora is a hard counter to poppy. in this situation, i will take last stand and triumph as my second rune. most likely ill ask my mid to help me too. since your Q does max health damage, always use it on her when possible and then disengage. kind of like and hit and run. after i get my armor, i will start to play like normal and pressure her hard since her late game isn't that strong. thats all. if you have any problems don't be afraid to ask! feel free to approach me to ask more questions so that i can improve myself as a guider too!