If I lived like it was the 80's what would I do instead if I don't have a landline phone?

you would have to use a payphone.

Most people would have party lines if they couldn't afford phone service, most everyone had a phone line in their home. If you can afford a smart phone now, you can afford a home phone then.

you would have to use a payphone.

You had the dubious pleasure of using a public telephone box, with its distinctive aroma of stale urine.

You would talk to people in person. 

We used them when we actually had something to say to someone else rather than just prattling on about a load of rubbish and we took a shopping list with us rather than having to phone home to see what we needed.

You would have had a hard time getting a job but might have been able to get messages from a close to where you lived friend or relative. 

You might have spent a fortune using your MCI calling card at payphones 

Find a pay phone, yell really loud, use a CB radio or if you were really rich, a cell phone. 

You would mail letters or visit people in person.

You would use a payphone.