Without knowing more about your interests, my top suggestion would be to focus on Sydney and Melbourne and the areas around both. The Blue Mountains near Sydney are also nice for a couple days or so. The main challenge you’d have in seeing a lot of Australia is that it’s all so spread out. You can hire a car for Melbourne and Sydney and that whole area, but it’s better to fly to get to Uluru (near Alice Springs) or Brisbane or Cairns/Great Barrier Reef or Perth. You’d be driving for days in between those places if you started from the southeast area where most people live.
I totally agree about the solo traveling thing being down to luck in many cases. Right now I’m on a long trip around Europe again, and from one night to the next I might meet a bunch of interesting people, or be sitting there alone in a sea of locals with no interest in chatting with foreigners. At least in a place like Goa, everybody is on holiday, so I’ve had good luck meeting people.
The next morning we hit up the hotel dining area around 7 am for a large breakfast before going out for our second day. They had gigantic breakfast bowls (Meal 3) as part of their offerings, so that’s what I got. I asked for a southwest bowl with no potatoes, and received a heaping plate of eggs, chopped ham, onion, green peppers, and melted cheese. I also got a side of bacon and had a fatty coffee that I made in my blender bottle with powdered coconut oil, liquid stevia, and half n half. I added some salt, pepper, and butter to my breakfast bowl and was very full. So full, in fact, that we did not eat again until 4 pm.
Two of the easier other choices would be London or Madrid. From Amsterdam you can take a train to Brussels and then change for the Eurostar train to London, or you can fly. From London to Barcelona you’d want to fly for sure. If you chose Madrid you can go to Amsterdam and then fly to Barcelona and then take a train from Barcelona to Madrid in only 2.5 hours.
I am planning a 12 night or close to 2 weeks holiday from London for the last week nov/or first 2 weeks of December to avoid the holiday season. Looking for a sunny holiday so nearest bets are a minimum 7 to 8 hr flight from here. I had few things on my mind mix a wildlife safari and beach holiday in Tanzania (but the safari’s appear v expensive!)or travel to south/central America I haven’t been to any part of south America and was considering costa rican region. Ideally looking for few days on a good beach snorkelling etc and few days exploring the country and nature. Do you think costa rica is a good starting point if it’s the first country I was visiting in south America ?
The rainy season is still finishing during November in Central America, but a bit north and south of that it's dry enough to make visiting very worthwhile. Better yet, it's still low season for hotels in most places even though the weather has gotten nice. Latin America is filled with excellent bargain choices and it has some of the best places to visit in November.
Southeast Asia is easier to deal with, and there are cheap flights connecting in the Middle East and landing in Bangkok, Kuala Lumpur, and Singapore. Each of those is a very interesting city, and there are many smaller places to go in the same region. In Malaysia there is Penang and Melaka. In Thailand there is Chiang Mai and quite a few others in that area. In Laos you can visit Luang Prabang, which sounds like it could be a winner for you. And there is also Siem Reap, which is home to the amazing Angkor Wat temple complex.