I will surely go there but I wonder if one day is enough to go around the park or is it better to go for several days?

Google roughly translates your question as is one day enough or should I go for multiple days. To answer your question, there are two parks, Islands of Adventure and Universal Studios Florida. The two parks are joined by a train in Harry Potter land. The only way to ride the train is to have a two park pass. If you're really fast you could do both parks in one day, but if you've never been to either Park I would suggest a 2day 2 park pass. That would allow you to go between parks on the train so that you can see it, and do all the attractions in both parks. If you only want to do one Park, then one day is sufficient.

I indicate at least 2 days in this park