Suggestions on places to solo travel in late January

Hello! I’m a 24 yr old female that’s looking for places to go to for 2 weeks near the end of January that’s warm. Cheap/mid budget(around 2.5k-3k usd) would be preferable. I love nature, mountains, swimming, kayaking, diverse wildlife & such. Night life isn’t a priority but it would be fun for a night or two. I’m way more of an adventurer than partying. Right now I have a few places in mind like Vietnam, Costa Rica, possibly Cyprus?, & Thailand…Australia would be fantastic but that might be over my budget. Thank you:-).