If you’re just starting out with Google Ads, it’s advisable to set a modest budget that you’re comfortable with and then increase it as you start to see results. You can always adjust your budget as you go along, so don’t worry if you don’t have a huge amount of money to start with.
In terms of how much you should spend on each click, this will again depend on your industry and what you’re trying to achieve. Generally speaking, you’ll need to bid more for competitive keywords than less competitive ones.