It says the headset is a VP Comp 1". But that isn't going to tell you what bearings you need. Most specifcations on bikes are determined by taking what you want to service apart and looking at it. If the headset has cartridge bearings, they will likely have markings. If not, they will be individual balls that you measure and replace with the same. Same with the BB or fork.

I strongly recommend you go to a bike shop if this is that unfamiliar. They can help figure out and sell you the parts if you want to attempt to do the work.

This was a very entry level bicycle, like something that would sell for $300 new in the US, at most. If it needs a new fork, it may not be worth repairing if there is enough wrong with it.