Once everyone knows what you are talking about, Spanish replaces the noun with lo, la, los or las and puts it before the conjugated verb. The pronoun matches the gender and number of the thing, not of you: la habitación becomes la, el desayuno becomes lo.
Examples
- ¿Tiene una habitación doble? Sí, la tengo.
- Do you have a double room? Yes, I have one.
- El desayuno está incluido, ya lo pagué.
- Breakfast is included, I already paid for it.
- ¿Las llaves? Las dejé en recepción.
- The keys? I left them at reception.
The mistake to avoid
The pronoun goes before the verb, not after it: la tengo, never "tengo la".
Where this fits in
Travel & directions, Spanish A2: Get around in a Spanish-speaking city: take transport, ask the way, check into a hotel, and buy a ticket.