Yes, that is exactly what 'Go ahead!' means. In fact, it's more appropriate than 'Carry on', because 'carry on' means continue something that you have started. For example, someone tries to interrupt you, but you carry on talking. If you haven't started your travels or your studies, you cannot 'carry on', but you can 'go ahead'.
For example, if someone says 'Is it OK if I open the window?', you can say 'Sure, go ahead.'
Your only mistake is that 'afford' is followed by 'to' and the infinitive, not the gerund.:
If you can afford to travel.... Go ahead!