They are very common abbreviations for "para aca". They are used colloquially in much of Latin American (not sure about Spain). People often shorten para. Another song is "Es Pa' Ti, Mi Vida". Another common shortened phrase is "mijo" (mi hijo, or mija).
Depending upon where the speaker is from, many people cut out the d near the ends of words. For example, "Estoy cansao." As with your first example, you probably would not hear this in formal language and not everyone does it.
There are lots of common shortened words. I'll just write the shortened version—see if you can figure out what they mean.
Mijo, ¿por qué hiciste eso?
Ayúdame con esto, por fa.
Ta loco, mano, ¿o qué?
Lastly, there are tons of words that seem a lot less informal, which are shortened often:
moto
bici
profe
uni
tele
These are just a few examples of a TON of shortened words out there, and they vary from region to region.
Espero que esto te ayude, aunque sea un poco. :)