Start with you budget limits first. Then list your wants vs needs. Remember many quilters/sewers never use all those fancy stitches anyway. Then do an assessment of your own: would you even consider a used machine. Many folk do upgrade to get the newest or newer features but trade in a perfectly good machine to help cover the cost.
Then try out all the machines. Look for good service and continued support as you learn the ins & outs of your newly purchased machine. Dealers will often times negotiate prices too.
Then: decide which machine you bond with and works best for your own needs. Personally I am a Pfaff person because I can still sew with the IDT [dual feed] feature. Also, for me a knee lever doesn't work as my thing goes numb using it. Thus you need to match the machine with your needs.
Years ago I was offered free a great machine. I tried it and it sewed beautifully. However it was hard for me to see instantly what stitch I had chosen. As my kids were still little I knew I would have a lot of distraction. Those two things were why I turned down that offer. Even after all these years, I am still glad I did turn it down.
Make the process fun.