I have a problem with first gear while slowing down it grinds going into first but when I’m parked up and go to pull away it’s fine and no grinding I’ve just had a new clutch put on would the clutch need more bleeding
First gear on most transmissions doesn't have syncromesh so you'll have to double clutch to get a smooth downshift into first.
They don't need syncromesh because most people don't downshift into first as part of braking/deceleration, but only once the vehicle has come to a standstill.
Recently, I've had two VWs, one (2011 Jetta) is reasonably easy to get into first while rolling, so it may have a syncro on first, while the other (2003 Passat) was nearly impossible to get into first while moving.
If you had a mechanic tell you that this was a clutch issue (and there were no other issues pointing to a clutch failure), I'd say the mechanic got some work out of you for nothing and I would recommend not returning to this guy.