First, this is a dangerous virus. Very little is being discussed about how dangerous it is, to avoid panicking the public, but the data is there. By contracting this virus, you run the risk of permanent lung damage or death.
Second, what makes you think you’ll gain immunity? At this time, a pattern has been noticed of some people either relapsing, or becoming reinfected. If they ARE being reinfected (it’s not yet entirely clear what’s happening), then you won’t gain immunity by getting sick with this. (And it will make a vaccine more problematic, too).