I found the following article that I think might help answer the question
Did John Calvin have a heart for evangelism and mission?
Dealing with predestination in the Institutes, Calvin does not directly address evangelism specifically, but neither does he describe it as unnecessary.
He does, in fact, write several times about the gospel being preached to the masses, resulting in the salvation of the elect and the hardening of the non-elect (III.23.10; II.5.10).
In other words, Calvin did not limit the preaching of the gospel to those considered to be elect. He explains his views more fully in his treatise on predestination:
Since we do not know who belongs to the number of the predestined and who does not, it befits us so to feel as to wish that all be saved. So it will come about that, whoever we come across, we shall study to make him a sharer of peace . . . even severe rebuke will be administered like medicine, lest they should perish or cause others to perish. But it will be for God to make it effective in those whom He foreknew and predestined.
Calvin clearly encouraged Christians to be involved in evangelism!
“It befits us” to desire all people to be saved.
The result of this proper desire should make us try to lead everyone “we come across” to faith in Christ, for that is the only way they could share in peace.
This is not to be a half-hearted effort. Christians are to use “even severe rebuke” if necessary to prevent others from ignoring the gospel and perishing. Christians must make the effort to evangelize everyone knowing that only God can save.
Read the rest of the article here: John Calvin on Evangelism and Missions