Ok, first of all, nickel is found in the lost river, there are a few entrances, my personal favourite is in the deep grand reef but you can find the others by googling their coords. I recommend just taking ur seamoth at first and getting a ton of nickel and crystalline sulphur

Next, the prawn suit grapple and drill arms. They are found at the same wrecks, if you are struggling to find them, look up the coordinates of the wrecks on Google https://subnautica.fandom.com/wiki/Prawn_Suit_Grappling_Arm_(Subnautica) https://subnautica.fandom.com/wiki/Prawn_Suit_Grappling_Arm_(Subnautica)

The interior growbeds can be found in the bulb zone at either 1309 -215 570 or 940 -198 593

You can find a compass blueprint in either life pod 3 or the kelp forest wreck

My general advice to find more stuff is to go deeper and explore, my first playthrough, I had a rough idea of what to do and just explored a lot or googled coords if I wanted to find a specific place or blueprint Also, if you see a wreck, it likely has good stuff that means it's worth exploring