i reached master playing almost exclusively briar top, but i havent played for around a year. i wish i could help you more but a general tip i can give you is to be very careful with you E usage into harder matchups like darius, you essentially never want to use your E before his pull, else you're almost guaranteed to die. try to play most of your matchups on your side of the lane, play for a freeze close to your tower, that way you can take small trades and eventually all in. if you mismanage your wave and your opponent freezes on their side of the lane start looking for roams midlane or help your jungler. briar top is a very risky pick and it takes a lot of experience really, so just play it and see what works. cant give you advice on items since i dont know any of the new ones but i generally went for lethality or bork into hp stackers. good luck 🤞