How to individually control ~100 LEDs
A few choices: 


You can use shift-registers such as HC595 to drive individual LEDs,
one resistor in series with each. Needs only 4 port pins from your
MCU, but n resistor and n/8 (rounded up) chips. It would be static
drive. 
You can use individually addressable RGB(W) LEDs and add color to
your project. Still only a few port pins. Libraries are available for
this purpose. 
You could build row and common drivers and multiplex the LEDs fast
enough that they appear to be steady. Time-tested approach, works
well. You could use (say) 8 column drivers and 8 row drivers to
control 64 LEDs.


Personally, for a hobby project, I would probably pick door #2.