When it comes to covenants there are unilateral and bilateral Covenants. The unilateral Covenant in the Bible is a promise from God without any conditions. The rainbow Covenant and the Davidic Covenant that his descendants would always be upon his throne are examples of unilateral Covenants. The bilateral covenants of the Bible are promises from God based upon conditions which must be met by men.
To hear the gospel and become a Christian is not an example of entering a unilateral covenant. If Calvinism were true, becoming a Christian would be an example of being in a unilateral Covenant because all of the conditions are established and kept by God without conditions on man. This isn’t Christianity and Calvinism isn’t Christianity.
In Christianity, God establishes the conditions for giving the promise of eternal life. And to receive this gift from God, which God without partiality offers to all the children of Adam, each sinner must believe and obey the Gospel, Romans 10:16; 2 Thess 1:8; 1 Pet 4:17. To obey the Gospel requires turning from sin, confessing Jesus is Lord, and then being baptized by adult immersion, Acts 8:12; 22:16.
I say this in love. Get a hold of me if this is something you need to do.