Do see the learning development lady as soon as you can, she will have contact numbers for the professionals you will need to see.
School have identified some areas of concern and they have suggested an Ed Psych assessment.
You may not realise it at the moment but you are very lucky anything has been picked up so quickly, so do go ahead and have the assessment, see what it turns up. Professionals don't diagnose things that are not there, see what the Ed Psych says.
A lot of parents on these boards are desperate for schools to notice their kids need help in some areas and the schools "see nothing" which makes the road to getting help a very long one form them. You've bypassed all of that.
Also, kids who try to be the class clown often adopt that strategy to cover up that they are finding some things difficult, again, go for the assessment. It will identify any areas he needs help with and there will be a list of recommendations for school to implement like slight changes to the way he's taught. There may also be recommendations for home too.
Remember, people aren't doing this to point out your son's "faults" they are doing it as they've seen he needs help in some areas and have suggested the assessment to pinpoint your son's needs and give strategies that will help him.
Have a look through this booklet, does anything in it apply to him?
www.falkirk.gov.uk/services/social-care/disabilities/docs/young-people/Making%20Sense%20of%20Sensory%20Behaviour.pdf?v=201507131117
If so, ask for referral to an OT that specialises in Sensory Processing.
Google hypermobile joints and joint hypermobility syndrome. Ask if you also need your son to see a paediatric OT for this. If so, make an appointment.