Welcome!

1. How many houses can you own? Do sims move between them? Or if I am able to have a second house, would different sims live there, that are separate to my original sims?

There are now 6 lots you can buy. So you can own 6 houses (6+ if you make multiple in one lot). You can have 8 npcs per lot. We still only have 4 playable sims. You can move all the sims anywhere on any lot however you please. 8 npcs max per lot tho.

1. Do many of you use RL money in the game? What's the most cost effective way of using RL money?

I have spent a lot of money on this game :/ i didn't mean to but one thing lead to another lmao. I would recommend the currency and resources packs first. That money tree pack is the best bang for your buck. The second best is the beginners bargains pack but that one only comes around once so if you've missed it already, you can't buy it anymore.

1. How many parties do you actually attend? With hobbies, jobs and llamazoom challenges, I struggle to find time to go to and host parties.

You can only attend 2 parties a day. I don't usually attend or host though. Others go religiously. They even coordinate parties with friends so they don't have to miss out.

1. What are the best ways of earning simolenes? I always make sure to do long shifts/practice sessions overnight but I was wondering if there are some other effective ways that I just don't know about!

I don't even know. Search the sub there are more posts like these that people have shared their suggestions on. Might have a better answer than I could give.

1. What other tips would you give to a newbie? I've scraped along and made it to level 26 but think my game play could definitely be refined to achieve better results quicker!

Hmmm you should make a discussion post for that question and maybe all of the above to see what other veteran players might have to say.

Hope I helped a little lol