Hello Aidex,
maybe you will use the Raspbian OS on your Raspberry PI board. If so, to install the Lazarus IDE and the Free Pascal compiler on it is easy, just open the terminal and perform the following commands:
sudo apt update
sudo apt install lazarus
The attached picture shows the Lazarus working on my Raspbian copy, I've used the commands above.
Cheers
P.S: It will install an old Lazarus/FPC, however, it works fine and could be useful for you to start on Linux.