Hi,
The PAYE contracts would be declared as employments, along with any tax deducted.
You can claim expenses for buying tools that you require to do the job in question. If this kit was acquired to do the contract work, then this would be an expense, set against the employment income. If aquired for use as a freelancer, this would be 'plant and machinery', which is a Capital Allowance you can use against the self employment income. You can see guidance here:
Claim tax relief for your job expenses
Claim capital allowances
Thank you.