I want to know from when can people start going for Umrah this year?
'Umrah/'Omrah العمرة has no special time in the year you can do it whenever you want to. You even can perform or combine hajj and 'Omrah at the same time, however the period of hajj is limited and fixed by the qur'an (Why Quran use 'Months' for period of Hajj?)... of course if a person wants to perform 'Omrah during the period of hajj it is highly recommended to combine both unless one had a reason for not doing so.
The 'Omrah basically, after an intention and wearing the ihram, consists of twaaf and sa'y which can be performed in a short time compared to the tasks of hajj, one might accomplish this in much less than half a day.
Also read the fatwa from islamqa #109313
The very simple question has been complicatedly answered here, after Ramadan every year the Saudi government stop issuing Umra Visas until completion of the Hajj. And even after Hajj for reasons of a thorough clean-up and Hujjaj to return back to their respective homelands NO UMRA VISAS are issued until start of Safar. So technically the Umra season starts at the begining of Safar and Ends at the End of Ramazan, by season i mean the ministry process of accepting applications and issuing of Umra Visas. And if you are locally present there requiring no visa for travel, you can perform Umra on any of the days except the Ayyam Ul-Hajj that starts in Dhulhijjah month and although Hajj is over in 5 days, Umra is not performed in the entire month of Dhulhijjah.