hao de pengyou vs huai de pengyou
很好的朋友（henhao de pengyou）basically means a 'good friend', that is, someone who is close to you, who you can share your feelings with etc.

eg  “他是我很好的朋友。”（ta shi wo henhao de pengyou）means 'He's a good friend of mine.'

好的朋友（hao de pengyou）on the other hand, mostly means someone who has good qualities, is kind, generous, faithful etc. And it is mostly used to contrast with 坏的朋友(huai de pengyou), who is the opposite of those good qualities.

eg. “好的朋友能让你受益匪浅，坏的朋友也可能让你误入歧途。” basically means 'a hao de pengyou will have a good influence on you, while a huai de pengyou may make you go astray (have a bad influence on you.)'

By the way, there's a Chinese saying which means almost the same. “近朱者赤，近墨者黑。” （jin zhu zhe chi jin mo zhe hei）means you'll get a good influence being around a hao de pengyou（朱）and a bad one being around a huai de pengyou (墨).

But note that the distinction between the two is not always so clear. As is “他会是个很好的朋友。”（ta hui shi ge henhao de pengyou）, which means that the person is a person of good qualities, and therefore you can trust them to become a good friend of yours.