I have not been for many years, but …….
Mud - every year you will see people on TV covered in mud.
But (except for the occasional truely flooded mud years) the mud is at the points that everyone walks through
I walked along the grass past the TV crew filming ‘the muddy festival goers’ who were walking and playing in a mud pit - performing for the camera
Crowds - it is vast. There are quiet spots
Generally wander around, if you see a highly congested point then just walk in another direction or stop and wait
The main pathways will be congested as an act ends on one main stage and is coming up on another main stage
If you absolutely must see a particular act then plan around being in the right area ahead of time - wander down in the middle of one of the preceding acts
Camping etc
Many years ago you could drive into a field and camp besides your car.
Back in the 90s I could drive and camp at some festivals but at Glastonbury even then you would park in one field then carry your tent etc to another field
When I as there as carer, I could drive into the disabled camping field - and on memory we parked nearby but not at the tents
VIP access - When we wanted to get to the pyramid stage we spotted a crowd ahead and a closed gate. So asked security at the closed gate what would be the best route at the moment. They looked at our lanyards and let us through
This took us to the VIP backstage area, and KT Tunstall said Hi to us mid interview
The next year we tried the same thing and were let through again - but this time there was a fenced pathway, we could see backstage to one side of the fence and the VIP zone to the other side of the fence
Disabled access would still have its privileges. You aren’t up close, but the wheelchair platform would tend to be below or besides the sound operator, thus being well placed for optimum sound
You also get a combination code for locked disabled portaloos and showers in the disabled camping
Bring wet wipes and a head torch to portaloos, as toilet roll disappears fast and you also want a good view of what state it may be in before you commit
Some will be nasty, but they get cleaned throughout - pick ones in less populated areas for the best experience