Hi Viridiana,
I'm 20 and I have had tinnitus for a little bit over a year, doctors haven't been able to find a cause but hearing loss has been ruled out. Everyones tinnitus is different. Since getting tinnitus I have attended a major american music awards show and four concerts, with ear plugs of course, and my tinnitus has remained unaffected. Some people feel that their tinnitus can be aggravated simply by driving their cars. Generally i'd say the amusement park should be fine, as long as your not standing directly next to any speakers. I'd bring ear plugs to wear if you ever get overwhelmed or to ease your nerves. Don't let tinnitus stop you from living fun experiences! (with protection of course). If you aren't in a good standing with your tinnitus yet though (as in being able to control your nerves and panic over tinnitus), maybe I would wait a little longer until you are more confident