The only way to level up in Pokemon Go is to gain experience, also
called XP. The easiest way to get more XP in Pokemon Go is to capture as
many Pokemon as possible. You receive 100 XP for catching a Pokemon,
but the game will award you with 500 XP if this is the first time you
captured Venonat, Pidgey or another Pokemon. You’ll even earn a modest
10 XP for a “nice throw.”
That said, you should capture the same Pokemon to get more XP in
Pokemon Go. It’s OK to have five Pidgeys because each one after the
first means 100 XP. And if you only want one Pidgey, you can transfer it
to the Professor for Pokemon Candy.
To transfer a Pokemon, press the Poke Ball icon at the bottom of the
screen and then access the Pokemon menu. Select the Pokemon you want to
transfer, then scroll down until you see the Transfer button. Choose
“Yes” to receive your reward.
Pokemon Go Tip: Incense will attract wild Pokemon to your Trainer for
30 minutes. Not a whole bunch, so don’t expect one Pokemon after the
other. You’ll earn Incense over time, or you can purchase some with
PokeCoins.