Keep a prayerful heart and seek God's leading when you host. In all things we need to be wise. Be careful about inviting ones who are forward and flirtatious. You have a marriage that is more important to protect than to host someone who could tear your marriage apart. This is why we must go into prayer and seek His will for our homes.
I have invited ladies and their children over from my church for food and fellowship at lunch-time. When we build relationships in our churches, we are building a stronger church. This promotes unity in our churches.
We have hosted a missionary family in our home. I am all about keeping things simple, instead of spending a lot money on groceries, and spending all day preparing it. We simply took them out to a local restaurant to eat. It ended up being cheaper than buying groceries would have been. Afterwards, we invited them back to our home for dessert and coffee. They blessed us so much when they shared all their stories with us. I love talking missionaries, they are so encouraging.
Hosting an elderly couple will be a blessing to you as a young couple. You will see a couple who has been married for decades. You will notice how they still love each other after all these years. You will notice how they love to have fun together. They will end up discipling you, and they will show you true hospitality.
To a stranger: I was a stranger and you took me in.
To someone who is hungry: I was hungry and you fed me.
To someone who needs clothes: I was naked and you clothed me.
To the missionaries who gave up everything to reach others.
To the Lonely, and to the hurting. God is asking us all to "be my hands, be my heart, and my voice."
Even Jesus himself showed hospitality without a home, and he fed five thousand.