Without money, no project! Even if your organisation is run by volunteers it is close to impossible to carry out a project with no costs at all.
Securing funds is a highly context specific challenge. One very useful way to start is by contacting your National Youth (Information) Council. It has expertise in giving advice on these kinds of matters, and no one will know the environment for youth participation in your country better.* Another way to secure funds is to prepare an application for a foundation or programme financing youth participation projects. For instance, have a look at the programmes of Erasmus+ and the European Youth Foundation to see whether your project matches one of their many yearly calls. And lastly, if a public administration has specifically asked for your project or endorsed it, you could ask them to find money in their budget to cover the project expenses.
When you have secured funds for your project, you have to draw up a budget – or modify the version you might have already made if you have applied for funds through a programme. Here the software Excel is your best friend. The number of different budget headings and the level of detail you should apply depend on your source of funding. You should always follow the budget rules of the funding provider! However, to give you an idea, some basic budget headings are usually costs for salary and costs for goods. When you have a clear idea about the budget available, it will be much easier for you to sketch a realistic eParticipation process. For instance, when you know the budget for goods it will be a guiding principle when deciding on the number and scale of your face-to-face participatory activities. The same goes for the budget for salary. This budget will help you assess the number of working hours you can allocate to planning and implementing the different project activities.
Keep in mind that a budget is not a stable document. You should adjust the budget whenever changes occur in your project plan. In other words, it always has to be up-to-date.