If you do not already have an expense account within your chart of accounts that you wish to assign this to then you can create a new one by going to accounting > chart of accounts > new.
You could create an account, for example Account type - 'Other expense', Detail Type - 'Other expense', *Name 'Training', and then select this account on the category drop-down when entering the expense transaction.
We're so happy to have you back, Nicola.
The steps provided by my colleague above is applicable in QuickBooks Online version.
For Self-Employed, we can record the amount of the training and and select the correct category. This way, the calculation will be included to your self employed taxes.
Here are the steps that will surely walk you through the process:
You can take a look at these articles for additional information:
Thanks for clarifying the version you're using right now. If you have additional question, you can post them here anytime. It'd be my pleasure to help and provide you further information about QuickBooks Self-Employed. Take care!