There is only actually one call for the Christian and that is to come into Christ and abide there in a life of consecration and sacrifice for God. Romans 12:1 tells us the present our bodies a living sacrifice which is our reasonable service.
As for what God wants us to do with our time and talents, He will reveal that in time if we are faithful to the small opportunities to use what we have available to us in His service.
Ask the LORD in prayer: What are my talents and abilities? Pray for a mind to be open to abilities and opportunities that we may not recognize.
We are all different! Romans 12:4-5
Consider the list of abilities in Romans 112:7-8: serving, teaching, encouraging, contributing to the needs of others, leadership, mercy (to compassionate by word or deed).
Which of these abilities am I drawn to and which do I have a passion for?
Our chief work as a Christian is to Preach the Word (again if you are faithful in the small opportunities—like your family and friends and people you come into contact with), perhaps if God will give you more opportunities. Preach His Truth, by word! by tract! by example! Isaiah 61:1-3 Plant kernels of truth and let God give the increase. 1 Timothy 2:24-25
Another work we are privileged to do is edify or uplift the brethren, to lay down our lives for the brethren. We can do that by visiting the sick and shut in, to write a card or call on the phone, give them a ride to church. Jude 20-21; Hebrews 3:12-14. Here’s an idea: Pray to be aware of someone need and then pray for a scripture verse to share with them and to pray on their behalf.
If we have talents for organization—we can organize and start up small Bible Study groups or special study weekends and get others interested in studying too. Maybe the LORD will use us as he used Timothy: Titus 1:5, to ‘arrange what is lacking.’
If we have a talent for singing—then sing hymns with the brethren when you visit the shut-ins or sick. Colossians 3:16
We are not to look for the grand opportunities for service if we are neglecting the small ones. But we are to be open to every opportunity that God puts before us to let our light shine.
Colossians 3:17: “And whatever you do, whether in word or deed, do it all in the name of the Lord Jesus, giving thanks to God the Father through him.”;
Whether we use words or actions, may they be in accordance with the character and authority of Jesus our Lord, motivated by gratitude to the Father.
When prayerful willingness and God directed ability meet opportunity that is Godly service!