Hey! It's great that your going to start uploading on Youtube, it's a very exciting start.
For myself I don't use free software since I purchased/have a discount through my school (I use Premiere Pro to edit and Action! to record then I use my video camera for my voice audio and face-cam)
But if you are looking for free software OBS would definitely be a great start. I have used streamlabs obs personally but I'm sure that they are similar enough to where you could just use either for recording and not streaming purposes.
As far as OBS tips the one by the Youtube channel TechGumbo is well explained (I can't post links yet since I'm new to the forums)
Side-tip: if your laptop fan get's too loud you may have to record in 30fps instead of 60 which shouldn't be really noticeable since it's the sims and not a first-person shooter or something.
Let me know if you need help on anything else! Best of luck!
