Yes — you can generally claim these as pre-trading expenses, and the rules are generous. For income tax, costs incurred up to 7 years before your trade began are treated as if they were incurred on the day you started trading, so long as the expense would have been allowable if you'd been trading. Your laptop qualifies as plant and machinery (claim capital allowances, restricted for any private use), and the training courses qualify if they were for your existing consultancy trade — the fact they were to get you qualified for this work rather than to update existing skills is actually helpful for allowability.
For VAT, the window is narrower: you can reclaim VAT on goods bought up to 4 years before VAT registration (only if you still hold them and would have been able to reclaim), and on services bought up to 6 months before registration. The training courses are services, so their VAT is recoverable if the invoices are within that 6-month window before your registration date; the laptop's VAT is recoverable on the 4-year goods rule.
Practically: keep all the invoices, log each item's purchase date against your trading start and VAT registration dates, and claim them in your first VAT return and tax return. Just make sure the laptop's business use is genuinely dominant — any personal use proportion needs adjusting.
