Welcome to the board!!
Instead of checking out "boxed" machines at box stores, go to a dealer and test drive a few. Try as many dealers as you can find in your neighborhood.
Be sure to ask about USED machines. Dealers take in old machines as trade-ins when folks upgrade. The dealer will have their tech give the old machine a good going over, cleaning, and do any needed repairs. By doing this you can afford more machine for your money. Make sure you get at the very least a 30 day warranty with the machine, but try to get closer to 90 days. If the dealer trusts their repair guy they should have no problem extending a warranty to 90 days.
I highly recommend this method, especially for folks on limited budgets who want either more bells/whistles, or a higher quality machine (quality components, ie metal gears instead of plastic). I purchased a used Janome 6600 for a very good price and have not regretted it for a second.
Also ... since you are only looking for straight stitch and zig zag, plus better lighting ... you might want to consider a vintage machine and add your own lighting. Some of them are almost bullet proof, easy to repair & clean yourself, and simple to operate.