Out of interest why are you only interested in from 2000?
You’re restricting yourself quite massively. Unless you mean performers/orchestras/conductors from then playing older music.
In which case I recommend Barenboim’s West-East Divan Orchestra. I saw them do Tchaikovsky’s Piano Concerto 1 with Marta Argerich at the proms a few years ago and it was fantastic.
If you’re completely new a piano concerto is probably a good place to start. Aforementioned Tchaikovsky 1 is good, Rachmaninov no. 2 is also a personal favourite.
All of Beethovens symphonies are good, 5 is very famous (dun dun dun dunnn) 9 is also very good. I’m a massive fan of Schubert’s unfinished symphony and his 5th symphony so I recommend them. Mozart there’s so many, but 40 and 41 are probably the most well known. Mozarts requiem is incredible so I recommend that too. I’m more into piano solo music but I would say that’s not the best to listen to if you’re getting into classical, stick to orchestral stuff.
Next summer I suggest going to the proms, you can turn up on the day and get ‘promming’ tickets really cheap for most days.