Hi, which is correct?

[Liquinn3]

Necesito un autobús a Barcelona
Necesito un autobús que viaje a Barcelona

Also, will I get a return ticket if I said the phrases or just a single ticket?

[Rusty]

Ask for a ticket to Barcelona. I don't think it's necessary to ask for a bus that goes to Barcelona, unless you're at a place that sells tickets for various modes of transportation.
If you're asking for a ticket, you would get only a one-way ticket. There is a way to ask for a round-trip ticket.

[Liquinn3]

Ask for a ticket to Barcelona. I don't think it's necessary to ask for a bus that goes to Barcelona, unless you're at a place that sells tickets for various modes of transportation.
If you're asking for a ticket, you would get only a one-way ticket. There is a way to ask for a round-trip ticket.
Necesito un billete a Barcelona.
Quiero un boleto a Barcelona.
Necesito un boleto para Barcelona.
Necesito un boleto a Barcelona.

Which is right? :)

[Rusty]

Much better!Necesito un billete a Barcelona. (OK) (Spain)
Quiero un boleto a Barcelona. (Quiero is too harsh a way to ask for something - boleto is used in Latin America - there's still a better way to phrase the sentence)
Necesito un boleto para Barcelona. :good: (the preposition used here is the better one to use - change 'boleto' to 'billete' and you're good to go)
Necesito un boleto a Barcelona.

[Liquinn3]

Quick question; what's the differnce between billete and boleto?

Thanks.

[Rusty]

Already noted above. The difference is regional usage. If you're in Spain, you use billete. If you're in Latin America, you use boleto.