Once Battle for Azeroth launched, Blizzard patched in the option for players to queue for the Looking for Raid version of Legion raids alone. This allows you to solo the entire raid if you are able to, getting all that cool transmog gear you might have missed when you played Legion.
It's very easy to get into Legion LFR raids, and just head to Dalaran. Go towards the Violet Hold and find Archmage Timear there. Speak with him to select the LFR raid you want to solo queue for, and you're good to go. You won't have to wait since you queue to play it solo, and you will be instantly teleported to the raid.