How can I get programming experience for the curriculum?

Question

Good jobs everywhere require a lot of previous experience, I've seen that many well paid jobs in big companies have 5 years of experience minimum.

For this jobs what's exactly experience and in which ways can I improve it?
Do I really have to have had previous jobs or things such as github contributions count?
Can I use work I've done as freelancer or I've to have had a physical contract with a company?

These may be dumb questions but as I'm a student and have never made a curriculum I don't know Thx ;)