Every Christian who wants to be used by God desires what is good. We who have been bought by the precious and priceless blood of the Lord Jesus Christ ought to keep in mind that we are not our own, that we belong to God and He owns us.
That said, I would encourage each and every Christian to desire to serve the Lord. It is not a burden, but a joy that will produce more and more joys. Think of what the Lord Jesus said about it:
"The kingdom of heaven is like a mustard seed, which a man took and sowed in his field, which indeed is the least of all the seeds; but when it is grown it is greater than the herbs and becomes a tree, so that the birds of the air come and nest in its branches." (see Matthew 13-31-32)
You may not start big, but if you start serving the Lord and just keep on serving Him, you will grow and soon find yourself doing things you've never thought you will ever do. Just start!
To encourage you and prepare you for service, here are few things you need to know.
1) Be prepared for chastening
God chastens those He loves. When we serve God and experience some sort of pain or hardship, even without doing anything wrong, realize that God is pruning us so we can bear more fruit.
Jesus said in John 15:1-2, "I am the true vine, and My Father is the vinedresser. Every branch in Me that does not bear fruit He takes away; and every branch that bears fruit He prunes, that it may bear more fruit."
2) Be willing to let go of yourself
When we desire to serve the Lord and follow Him, we should couple this with the desire to have less of ourselves. Self-denial has to go with following Christ, or else it will be just self-punishment. They have to go together. We can't follow Christ without denying ourselves.
Jesus said in Matthew 16:24, "If anyone desires to come after Me, let him deny himself, and take up his cross, and follow Me."
When we are full of ourselves, we won't be able to serve God. We won't even be able to serve people. All we'll ever think of is ourselves.
Paul said this is also the same when it comes to the Spirit. In Galatians 5:16-17 he said "Walk in the Spirit, and you shall not fulfill the lust of the flesh. For the flesh lusts against the Spirit, and the Spirit against the flesh; and these are contrary to one another, so that you do not do the things that you wish."
3) Don't ever look back
Lastly, keep in mind that we should be forward-moving, not the other way around. Jesus said in Luke 9:62,
"No one, having put his hand to the plow, and looking back, is fit for the kingdom of God."
When we choose to serve the Lord, we should go all-in. We must never desire going back to who we were before He saved us. We must forget the past and move forward to God's purposes for our lives. Isaiah 43:18-19 tells us,
"Do not remember the former things, nor consider the things of old. Behold, I will do a new thing, now it shall spring forth; Shall you not know it? I will even make a road in the wilderness and rivers in the desert."