Just started to work on intervals now to get myself faster

this is what i did

2 minutes easy spin, 1 minute hard
do this about 20 times.

seemed to work quite alright actually.

Does this sound effective as one formula

other why not and what should i be focusing on

i want to be able to ride faster, developer better power and speed.

Have a look at the sticky in the racing subforum. There are many good suggestions for intervals targeting different subsystems.

You can't possibly tell after one session of intervals whether it was effective. You need to do them consistently and have some way of monitoring your progress.

Normally, you would start out with longer intervals and build up your threshold power. You want to work up to 2x20 or 3x20 intervals at 90-100% of FTP. Save the shorter higher intensity intervals for later.