I have only personally ridden on Gary Fishers, Treks, cannondales, and GT bikes. Among those 4 brands that I rode, there wasn't much difference between bikes made with similar materials and components other than price. A used bike that's been tuned up is just as good as a new one. As a teenager in the 1990's my first bike was a 10 speed Raleigh from the 60's. I got the bike for free and had to replace the tires, tubes, brakes, gears and chain. I was lucky that the front and rear derailleurs were in good condition after all that time, those are a bit more pricey to fix. I've purchased many high end bikes used for cheap because people with tons of money to burn want something fancy, then end up never using the damn things except to ride around their neighborhood. If you're just starting out, get a used bike. This way if you decide it isn't for you, you haven't spent a mortgage payment on the damn thing. Something like this is likely up your alley brand new: https://www.giant-bicycles.com/us/contend-3 The frame here I believe is an aluminum frame and it's kind of what you would spend these days for something entry level. Trek and cannondale entry level bikes are even more expensive. The last road bike I had was a women's specific trek, hybrid carbon fiber/aluminum. I spent $1400 on that bike new 20 years ago. I rode that bike for 20 years, and I would still have it if it hadn't been stolen. If you properly maintain your bike it can last a lifetime.

When purchasing a bike, imagine a triangle. One side is cost, one side is strength, one side is speed. Pick two. A cheap strong bike sacrifices speed. A cheap fast bike sacrifices strength. A strong fast bike sacrifices money.

Do not shop for a new bike at department stores like walmart, target, or places like dicks sporting goods. The bikes get assembled by random minimum wage workers that don't know what they are doing, you'll end up with something that is poorly tuned right out of the box. New bikes generally need tweaking no matter what after being ridden for a while because the break/shifter cables stretch out a bit once you start riding. Find a local shop that only sells bikes. You might be able to find models that are a few years old, but still new at a better price than the latest bike to hit the market. Bike shops might also have a good selection of decent used bikes to sell too.

If you are considering a used bike, I would encourage you to find a well respected local bike shop that sells used bikes. Buying off Craigslist or other used item platforms can be fine too, but if you are just starting and don’t know much about bikes yet, it can be risky.

If you’d prefer a new bike, I might recommend a Canyon. They are a direct to consumer brand so the prices are typically quite good, and you get much better specs for the price than you would with brands that are not direct to consumer.

Canyon have just released an Endurace Allroad which is a fantastic entry-level road bike. The geometry (how the frame is arranged) is very friendly for newer riders, as it won’t have you stretched out in a very uncomfortable position. It has quite good components (parts) for the price. Unfortunately I think it is a little more expensive in the US vs in Europe.

Here is a video about the bike from a cycling YouTube channel that is quite good. They focus on discussing how bikes would work for regular people, not star athletes. https://youtu.be/KoEOayjg0B8

If you’re in Europe and you have access to Van Rysel, they also have some quite good entry level road bikes. The same channel as above (Cade Media) have some videos about them.

Happy to answer more questions if you’d like.

Edit to add: in the video they criticize Canyon for the component sizes. I agree with this to an extent. They definitely exaggerate the scale of the effect. For example they mention a person buying a 2XS being on 40 cm width handlebars and Francis holds his arms out extremely wide. In reality this isn’t a super big deal. My Canyon is that size and came with those bars and it was not a big deal. After a year and a half I swapped them for narrower bars but had no issue with them in the meantime. So in the end - is it the very very best component sizing? No. Is it bad? Also no. It’s fine.