No, for a number of reasons.
1) You may be allowed to use the internet for personal use, but you will almost certainly NOT be able to connect a personal device to the office network, for very good reasons.
2) Connecting a phone to a computer which is in turn connected to the office network is exactly the kind of thing a hacker would do.
3) A network adapter in a computer can only connect to one network at a time, so if your work PC is connected to office wifi then it cannot also connect to your phone via wifi unless it’s got two wifi cards, which is unlikely.
4) If you are connected to wired office network, then your PC might have a wifi adapter, but you would have to set that up to use the ‘internet connection sharing’ feature or whatever it’s called nowadays, and that would require more privileges than you probably have.
You might have an office guest network – try asking for access to that from your phone. They should be aimed at letting any random guest device onto the internet. IF they let you on it.