Why can't I capture my first Pokemon?

Solution 1:

You need to restart the game and try again. There is a huge load on the servers as they are adding new countries to the list where Pokemon GO is available.

If restarting the game doesn't work, reinstall it. If that doesn't work, have patience and try in a few days.

Solution 2:

Now the game is deployed almost everywhere, so you can reinstall it, and you'll be able to catch millions of Pokemon ^^

By the way, if you want to have Pikachu instead of the 3 other starters, you just have to walk a little bit (like 5-10 mins), and you'll see him spawning near to the starters ^^