Compiling an existing C++ program using Makefile - c++

Question

Edit: not solved, but as I moved on to other software, I ran into other challenges.
For a research project, I downloaded a Github project (Tagliasacchi et al., 2015) for computer vision to Linux 16.04. I have programming experience with PHP but I am new to C++. When I try to replicate the results of the study on my computer, I run early into a compiling error.
The Hello world-example of the Github project (apps » helloworld) works fine.
When trying to compile another application, I run into an error with the Makefile: cmake . works fine and some files are created. However, make does not work.
After the error, g++ [filename].cpp -o main obviously does not work.
How to solve this and get the dependencies right?
In some cases, there is a Makefile, but I run into an error:
[ 33%] Building CXX object CMakeFiles/helloworld_atb.dir/main.cpp.o
/bin/sh: 1: /usr/bin/g++-4.8: not found
CMakeFiles/helloworld_atb.dir/build.make:62: recipe for target 'CMakeFiles/helloworld_atb.dir/main.cpp.o' failed
make[2]: *** [CMakeFiles/helloworld_atb.dir/main.cpp.o] Error 127
CMakeFiles/Makefile2:67: recipe for target 'CMakeFiles/helloworld_atb.dir/all' failed
make[1]: *** [CMakeFiles/helloworld_atb.dir/all] Error 2
Makefile:83: recipe for target 'all' failed
make: *** [all] Error 2
In other cases (e.g. in tracker » HandFinder), I can't run either cmake . or make and compiling using g++ HandFinder.cpp -o handfinder does not work:
In file included from HandFinder.cpp:1:0:
HandFinder.h:2:41: fatal error: tracker/ForwardDeclarations.h: No such file or directory
compilation terminated.