No . He says that of first ( importance) thing was the Gosepl. its the most important thing. He would have taught other things . But the first thing was the Gospel.
1 Cor 15:1-4
1 Moreover, brethren, I declare unto you the gospel which I preached unto you, which also ye have received, and wherein ye stand;
2 By which also ye are saved, if ye keep in memory what I preached unto you, unless ye have believed in vain.
Paul goes on to remind them of what he shared first indicating other things were shared as well;
3 For I delivered unto you FIRST of all that which I also received, how that Christ died for our sins according to the scriptures;
4 And that he was buried, and that he rose again the third day according to the scriptures:
(see Acts 2. 8. 10. 19, etc. all begin by sharing Jesus' death, burial and resurrection afterward giving commands that require obedience.)
He then addresses who saw Jesus after His resurrection:
5 And that he was seen of Cephas, then of the twelve:
6 After that, he was seen of above five hundred brethren at once; of whom the greater part remain unto this present, but some are fallen asleep.
7 After that, he was seen of James; then of all the apostles.
8 And last of all he was seen of me also, as of one born out of due time.
The rest of the chapter is dedicated to concepts associated with resurrection such as the one's below:
15 Yea, and we are found false witnesses of God; because we have testified of God that he raised up Christ: whom he raised not up, if so be that the dead rise not.
16 For if the dead rise not, then is not Christ raised:
17 And if Christ be not raised, your faith is vain; ye are yet in your sins.
18 Then they also which are fallen asleep in Christ are perished.
19 If in this life only we have hope in Christ, we are of all men most miserable.