I'm hopeful that I'm being specific enough to avoid being too broad/subjective. I would appreciate any pointers or edits where required to make this question work here.
I am a non-road-warrior/seasoned-traveller from the North East of England. I'm very inexperienced with regards to travel and I know very little about locations outside of the UK. My holidays have been almost exclusively in Scotland or the lake district. I've never been on a plane and the furthest I've ever travelled is Paris (didn't care for it - Disneyland was ok) and I'm pretty nervous about travelling in general.
My partner is somewhat different. She loves to travel and has been to china and on a few Mediterranean holidays etc. She's pretty adventurous and not a big worrier like me. She'd like me to pick a destination to travel to for my 30th.
We'll have a budget of <£1800 for travel and accommodation and I can't get more than 9 consecutive days away from work. I'd like to travel to a location that is reasonably safe (low crime rate) and friendly (accepting of foreigners), and English speaking would be a bonus. I'd rather it take less than one day to actually get there (and the same back - so probably Europe?). Neither I or my partner are particularly interested in a 'nightlife' or just lying on a beach for a week, and I'm not much use when it comes to activities like white water rafting etc. Easy going hiking, seeing a bit of nature and some nice, unusual landscapes, preferably with mild-cold weather would suit us both I think (/hope). We plan to travel in October. I don't think I'm allowed to say 'Scotland' (again).
I'd like an answer to cover what I need to know or should consider when choosing a location; What sort of costs (particularly hidden costs) I should be aware of; and I'd very much appreciate any suggestions of countries or regions that I should investigate based on my criteria.
Update: I should have mentioned that I had considered a cruise but my partner dismissed this based on the unpleasant thought of being cooped up on a ship with lots of people (we're not very social) and having only a tiny cabin to retreat to. A shame though because I like boats and I'm not keen on the thought of flying... (airports creep me out)