You can appear  JEE Advance consecutively 2 times. There is no age limit present.Since, you have appeared JEE Advance in 2018 that makes your 1st attempt.So, you can surely attempt it this year.

Work hard. I wish you lots of luck.

If you need questions to practice for the jee advance you can freely download them from the following site:
https://engineering.careers360.com/download/jee-advanced-sample-papers-previous-years