You dont need to upgrade your gear for normal raids, and those net you around 40k a day. This will get you all the mounts you need in under 2 weeks. After that start upgrading and do all the other difficulties. Running all the normal raids is pretty fast and chill.
I know this might come across as the usual answer “just make your own group” but really just give it a try. You will be surprised how easy it is to create one, you dont have to “raid lead” or even talk to anyone or say a word if you don’t want. The raids on normal are so easy it runs itself, give assist to the tank they will do the rest from there.
Try to invite people around 340 ilvl which is what most level 70s have who have done the raids at least once. This way you will know they have experience.
Im around this ilvl and last few days it started to take longer and longer to get into groups due to people upgrading. Started making my own groups and had nothing but positive experiences.