I recently joined this project, but so far every single job I got for it returned an error within 3 seconds of starting the task. Is the problem with me only or are others getting this too.

On an unrelated matter, my user name doesn't show up in the BOINC manager, but it's set on the website, same as with the other projects I am in. It does show up there.

Hello Sibe Bleuzé.

your tasks have the same following error :

NOTE: VirtualBox has reported an improperly configured virtual machine. It was configured to require
    hardware acceleration for virtual machines, but your processor does not support the required feature.
    Please report this issue to the project so that it can be addresssed.
    Error Code: ERR_CPU_VM_EXTENSIONS_DISABLED

It's a common mistake, a configuration issue. Philippe, a user did a tutorial on this subject, just in the subject behind your post :
https://quchempedia.univ-angers.fr/athome/forum_thread.php?id=44