I don't know if I am going to be of much help, I have only every had a sewing machine that I inherited from an Auntie which did forward and back, straight and zigzag!

Having said that it was an awesome little workhorse. I have been sewing since a child and have completed many projects on it from clothes to home furnishings. I have recently begun quilting too. I don't even know the brand it is so obscure. The point is, a simple machine is a good place to start to get the hang of the basics. I am a fan of old school machines though, they just feel so sturdy and reliable. I hate the plastic feel of cheap new ones!

Recently I decided to 'upgrade' and bought a 1960's Janome Memory Craft on ebay for under $100. It was such a great buy and I have thoroughly enjoyed some of the little benefits of a better machine such as push button reverse . Maybe ebay is a good place to start with a cheap old machine to get you going before you work out what you want to spend your $500 on?? It will get you sewing!

Re: overlockers. No, strictly speaking you don't need one. I have survived 20 years sewing without one and just done a zigzag or used pinking shears where necessary.

I did recently get one - again on ebay from the same woman I got the Janome. I only got it because it was available from the same seller - ease of pickup - and meant I was getting a machine and overlocker for less than $150. It certainly has been nice, but still not "necessary" for my sewing. I am planning on making some baby wipes and I think It will come in handy for those though.

Hopefully someone else will have some more up to date advice about machines out there... otherwise, maybe you could pop into a store for demos or visit a service store for a chat about reconditioned models?