You need to download and install all three packages fpc, fpc-src and lazarus.

fpc-laz - the Compiler, some command line tools, base units and non visual components like database access
fpc-src - the sources of fpc and its packages, needed for code browsing
lazarus-project - the IDE, visual components and help files

* For an overview what changed from previous 2.2 versions
(includes incompatibilities with earlier versions) see:
- https://wiki.lazarus.freepascal.org/Lazarus_3.0_fixes_branch

* For an overview what changed from previous 2.2 versions 
(includes incompatibilities with earlier versions) see:
- https://wiki.freepascal.org/Lazarus_3.0_release_notes
- https://wiki.lazarus.freepascal.org/User_Changes_3.2.2
- https://wiki.freepascal.org/FPC_New_Features_3.2

* Checksums can be found at https://www.lazarus-ide.org/index.php?page=checksums

* For additional information visit our homepage, forum, wiki, and FAQ:
-- https://www.lazarus-ide.org/
-- https://forum.lazarus.freepascal.org/
-- https://wiki.lazarus.freepascal.org/Lazarus_Faq