Help needed merging everything from macbook air to imac - noob

[Nutrino]

Hi - just got an imac from a friend and have been searching everywhere to find a way to shift everything from the macbook air laptop to the imac. I've found bits and pieces for individual processes but I'm wondering if its possible to just take everything from the laptop to the imac desktop without having to do it individually. I would also be up for remote control of the laptop if its not possible to complete the system wide merge but I could use advice, thought, comments and a good kick in the **** if this is a bad idea. I now have two macbooks and feel like all my digital data is spread out all over the place and really could use advice on consolidation. I'm sure this topic has come up before but -noob here and I searched "merge" and "transfer" and yet the search box brings back a blank page telling me to keep searching. Sorry for the repost if this is the case. Cheers! and thanks for the help...

 

[badshoehabit]

Have a read through this. https://support.apple.com/en-us/HT204350