Holidays with toddlers can be extremely stressful and unenjoyable, so I think you're right to keep things simple. Our first holiday as parents of two DC was a week in a SC cottage in Lyme Regis. It had a washing machine, parking space right outside and was perfect. I didn't feel up to much more than that with a 3-year-old and a 4-month-old, but we've been abroad many times since.
I think the main thing I would say is to still keep it simple. Go to places you know, or know of (via recommendations of people you trust), keep travel time to a minimum (local airport, short flight, short drive other end, or similar drive/ferry), and source places that have a lot of the baby/toddler stuff there for you when you arrive (cot, potty, high chair, microwave, washing machine, etc). The MN travel recommendations were a godsend when our DC were small and we got several really good tried-and-tested places off there. Sites like 'BabyFriendlyBoltholes' are excellent too for the kind of ultra thing you need right now (fenced pools with gates, step-free access and baby and child clobber provided).
Just accept that holidays with DC are never as relaxing and lovely as they were pre-DC, that many people LIE about how great their holidays with babies and toddlers are, or they take the GPs with them and get some babysitting thrown in. It is possible to have nice family holidays though with good planning and low expectations beforehand. And remember that it DOES get better. My two are now 6 & 9 and holidays are actually quite enjoyable again now. I even get an hour or so by the pool with my book on occasion 