Question: I've never played Pandemic, but thinking of getting the Legacy edition. Is it possible to play it without the legacy elements a few times first, and get an experience that is same or similar to that of the regular Pandemic?

Answer: 
Yes, you could play something very similar to vanilla Pandemic using just the base game components and ignoring all the Legacy elements. The board is slightly different, but you probably won't even notice.

You can really only do this before you start playing the legacy version though. Once you start playing the legacy version, things will happen that will modify the game in ways that will quickly make it difficult or impossible to play the base game.
In fact, the Legacy rules themselves suggest playing a few games if you aren't familiar with Pandemic.

> 
> IF YOU'VE NEVER PLAYED PANDEMIC...
> 
> 
> We recommend that you play a few games without any of the special
> "Legacy" rules to get a feel for the decisions you will have to make.
> 
> 
> Read this rulebook then play without using the following rules:
> 
> 
> •Game Months, Legacy Deck, Dossiers
> 
> 
> •Objectives, Funding, Game Calendar, Panic Level
> 
> 
> •Scars and Lost Characters
> 
> 
> •Game End Upgrades
> 
> 
> The object of these warm-up games is to cure four diseases before any of
> the game-losing conditions are triggered (noted on page 14 of these rules).
> You should play at least two games this way to get a feel for the game before
> adding the additional rules.
> 
> 
>