First, I am assuming that you are using at least the standard or higher version of SQL Server.
I think the Express version does not have the agent.
The SQL Server agent - account - can be found under the configuration manager.
You should never use services.msc since a certificate is created when settings are changed.
Usually a domain account is supplied and is part of the local admins group on the machine.
However, other setups might be dictated by your company.
The Matrix at the end shows what accounts are possible to use and limititations.
If your account used by the agent allows logins into the server, ask your DBA to MSTSC into the server and try running the BULK INSERT. If this does not work, your account does not have the rights.
If this does work, then your SQL Server Agent is not configured correctly.
Like always, more detail and screen shots help us get to the root of your problem.