I want to find my macbook back , I sign out by myself

Unfortunately, the situation is a bit complicated because signing out of iCloud removes the device from Find My and deactivates the Activation Lock.

If you fully signed out, the Mac is no longer linked to your account. Consequently, you can no longer track its location on the map, play a sound, or activate "Lost Mode" via the iCloud website.

Apple does not track or locate devices using the serial number upon user request. However, you will definitely need the serial number to file a police report.

Since you signed out, you also removed the activation lock. This means you cannot lock it remotely.

If you had set up a firmware password (before giving it to your friend), or if your friend had subsequently signed into their own iCloud ID and turned on "Find My", the Mac will require those credentials to be formatted or reused.

Recommended steps to take immediately:

Log into iCloud.com/find from another device or check your device list from your iPhone. If for some reason the sign-out process didn't complete successfully, you might still see it there, allowing you to remotely wipe or lock it.

If your friend set up their iCloud ID on the Mac before it went missing, they can locate or lock it using their own account.

Find the Mac's serial number (you can look for it on the original box, the purchase receipt, or under your Apple ID profile list of previously owned devices) and report it stolen to the authorities. If someone takes it to an Apple Service Provider or if it is recovered by the police, the serial number is the only way to prove it belongs to you.

Just to be safe, if you think the Mac could be unlocked, change your Apple ID password and any other important services you frequently use.

"I want to find my macbook back , I sign out by myself for my friend and now it's disappeared without track, Can I find it by serial number or old ICloud ID or else Can i make it useless?"

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Not Seen in Find My:

If not seen in Find My, then it's been disconnected from Find My. You need to turn it on on the device, itself. If your friend has it assigned to their account,t hen they'll need to share it. Elsewise, use a third-party app (i.e. LoJack), and you'd see it. It takes a few hours, and up to a day to see it. Tahoe is proposed not to work with Find My, but works just fine. A bit odd, but so.

“Totally, and he disappear now, I already filled police, but they act like nothing lol”

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Locating your Friend:

If your friend disappeared, then that’s a case of its own. If they’ve disappeared on Find My, then they turned off location services(for privacy and security). So, if you get an email, overview it’s headers to find this IP Address, as it may lead you to somewhere close by.

Adding the detail 'I logged in with HIS account' completely changes the situation. It means that the MacBook is now officially linked to your 'friend's' iCloud ID.