The first SJPN should be dealt with in the "normal" way. Assuming you plead guilty it will be dealt with by the Single Justice and you will be sentenced (one third of a week's net income, a surcharge of 40% of the fine, £90 costs and three points).
The second one is different. It will not be dealt with under the SJ procedure but instead it will be listed for a hearing in the normal Magistrates' Court and you will be invited to attend. You will face a 6 month ban under "totting up" unless you can persuade the court that you or others will face "exceptional hardship." Here's the Magistrates' guidance when dealing with such a plea:
When considering whether there are grounds to reduce or avoid a totting up disqualification the court should have regard to the following:
It is for the offender to prove to the civil standard of proof that such grounds exist. Other than very exceptionally, this will require evidence from the offender, and where such evidence is given, it must be sworn.
Where it is asserted that hardship would be caused, the court must be satisfied that it is not merely inconvenience, or hardship, but exceptional hardship for which the court must have evidence;
Almost every disqualification entails hardship for the person disqualified and their immediate family. This is part of the deterrent objective of the provisions combined with the preventative effect of the order not to drive.
If a motorist continues to offend after becoming aware of the risk to their licence of further penalty points, the court can take this circumstance into account.
Courts should be cautious before accepting assertions of exceptional hardship without evidence that alternatives (including alternative means of transport) for avoiding exceptional hardship are not viable;
Loss of employment will be an inevitable consequence of a driving ban for many people. Evidence that loss of employment would follow from disqualification is not in itself sufficient to demonstrate exceptional hardship; whether or not it does will depend on the circumstances of the offender and the consequences of that loss of employment on the offender and/or others.
A couple of things spring to mind:
Were you not offered a fixed penalty for the first of these offences, or is the SJPN the first you have heard since you named yourself as the driver?
Check the dates on the SJPN. It must be issued within six months of the offence date.