The basic steps of Mashiach and beyond:
1 – Mashiach comes before the year 6000, with enough time to have a bunch of festivals as is clearly stated by many commentaries dealing with how certain festivals will or won’t be celebrated in the times of Mashiach.
2 – The yearr 6000, the physical universe goes kaboom, and all humanity “dies” so to speak.
3 – The next 1000 years HASHEM creates a new world that will be Olam Haba.
4 – Year 7000 – Olam Haba starts.
5 – Year 8000 – New things are introduced (see weird seforim for more details. Disclaimer: you won’t understand a word of it.)