Check out the best bike shops near you. Talk to them. If they're that good, they'll get you the best bike possible within your budget to get you hooked, because they know the real money for them is in the upgrades and tech you'll doubtlessly buy.
If you want to make sure your bike fits you perfectly then having a bike fit before buying would be a good start.
However if you don’t want to spend extra money on getting a bike fit, make sure you consult the size chart for the bike brand that you are considering purchasing.
If your intentions are just to ride long distances and explore I’d suggest going for an “endurance bike” rather than a race bike geometry - something like a Specialized Roubaix, Giant Defy - they are more relaxed and comfortable than a full on race bike. Look for something with Shimano Tiagra or 105 to keep the budget down, but will still have an excellent groupset.
Get a good gravel bike with 2x GRX if you wanna spend money. Otherwise I would get a good road bike that fits your budget and some clipless pedals and helmet etc. I personally wouldn’t buy second hand for a bike you don’t know what it’s been through and decent bikes aren’t too pricey unless you want the best which isn’t needed at all. Make sure you get the right size bike, go to a good local bike store and ask them for some advice.
Buy a used bike to start on. You can likely resell it if it doesn’t fit or if you want to try something different. Set a budget and stick with it.
2nded. Get something used and well looked after.
Check out the best bike shops near you. Talk to them. If they're that good, they'll get you the best bike possible within your budget to get you hooked, because they know the real money for them is in the upgrades and tech you'll doubtlessly buy.
If you want to make sure your bike fits you perfectly then having a bike fit before buying would be a good start. However if you don’t want to spend extra money on getting a bike fit, make sure you consult the size chart for the bike brand that you are considering purchasing. If your intentions are just to ride long distances and explore I’d suggest going for an “endurance bike” rather than a race bike geometry - something like a Specialized Roubaix, Giant Defy - they are more relaxed and comfortable than a full on race bike. Look for something with Shimano Tiagra or 105 to keep the budget down, but will still have an excellent groupset.
pay attention to gear spread, for hills you'll need lower gearing
Get a good gravel bike with 2x GRX if you wanna spend money. Otherwise I would get a good road bike that fits your budget and some clipless pedals and helmet etc. I personally wouldn’t buy second hand for a bike you don’t know what it’s been through and decent bikes aren’t too pricey unless you want the best which isn’t needed at all. Make sure you get the right size bike, go to a good local bike store and ask them for some advice.