@karlywaam,
many ways - the thing is finding what YOU like to do.
Some things could be if you like music and dancing - there are fitness classes around that. If you like team sports - just playing recreational sports might be your thing. Sometimes just changing up what you are doing helps - if you run on a treadmill - maybe go running outside.
Is there a sport or something you like to do? Have your fitness centered around that - if you like to be around other people join an exercise class. If you like the outdoors go hiking.
The thing is it can be fun - you just have to know what your "fun" is.
For example, I live where it gets very cold in the winter. I used to live near a bike trail and people would cross country ski on it in the winter. I bought some cross country skis, learned how to use them and viola - I found something I could enjoy in the winter and get exercise.