First, you'll need some friends to fly with. Tackling is about PvP, and while you can certainly PvP alone, I wouldn't recommend that in the very beginning.
The job of the tackler is to prevent the enemy from getting away. The warp disruptor and warp scrambler modules will prevent an enemy from activating their warp drive and fleeing. A warp scrambler also disables the enemy MWD, slowing them down, but has a much shorter range than the warp disruptor.
The absolute minimum requirement for tackling is to be able to fly any frigate and to use either a warp scrambler or warp disruptor (which requires the Propulsion Jamming skill).
Then you need a cheap ship and a minimal set of skills. The best ship to start would be one of the T1 attack frigates, as they get a bonus to the cap usage of tackle modules. Those frigates are
- Slasher (Minmatar)
- Atron (Gallente)
- Condor (Caldari)
- Executioner (Amarr)
Choose the one where you already know the frigate skill, which corresponds to your starting race at the very beginning.
I strongly recommend you to read the Newbie Tackling Guide from Azual Skoll, it goes into much more detail and also contains some example fits. Just take one of the example fits and plug it into EFT or Pyfa to see which skills you need to learn to use all of the modules.