@JudyN Most 'attachments' are fitted onto older machines by screwing the said attachment to the needlebar, be they zig zag, binder, zip foot etc. I don't have a great deal of knowledge very modern machines and/or if some are clip on types if available. They are not that difficult to fit, plan your work, attach said item, complete work and detach same. Yes you have to take off and reinstall your usual presser foot for normal straight and zig-zag stitches, but I have attached them (albeit slower than I would like to) depending upon my dexterity on any given day, hence I said plan your work.
An older machine with the capabilities you seem to require shouldn't present any more difficulty dexterity wise to enable you to use attachments than a more modern lighter weight machine.
ETA Buttonholes, depending upon your machine, may require a 'specialised' foot. It depends on your knowledge of your machine and its capabilities. An excellent Satin Stitch and a machine with adjustable zig zag width, you can make a good straight buttonhole, a 'keyhole' buttonhole takes some mastering unless it's on a modern machine wit built in buttonhole variations.
For me, it's lifting, shifting and positioning the machines that present problems. If you can leave your machine in situ until you are able to use it, that's a bonus.
Take all advice offered by members here and practise.... Ask again if you hit a hurdle.
We were all learners once.