also i forgot to work with ssms i wanted to install sql server. so i installed ssms first and then moved to this. i dont think this matters but just wanted to state it.
Don't know exactly what this means, but SSMS and SQL Server are separate installs. If all you are saying that you first installed SSMS and then SQL Server that should not matter.
so this is my private laptop bought it a few days ago. and i dont have any other antivirus only windows defender
Maybe you should double-check, so that the vendor hasn't sneaked an antivirus you did not want. Then, an antivirus that bites on SQL Server - that's a little extreme.
Did you check the event viewer if there was an error message related to your attempt to start SQL Servre?
This is not a funny situation. You could use Process Monitor from sysinternals when you try to start SQL Server from the command-line window. Then you might find where things go wrong. But this is definitely troubleshooting on the advanced side. It can easily take you deep into the rabbit hole.
The other alternative is to use Docker to create a virtual machine and install SQL Server on the VM.