Earlier, I asked for input about what a beginner in their 30's can expect and I appreciate all the helpful information/ideas etc that were provided.

I got a basic computer and for the past week or so I've been getting out roughly every other day and going around 20-30km, averaging around 24km/hr on extremely flat terrain with little to no wind. I've noticed that I'm starting to be able to go longer with slightly higher average speeds and have been feeling good about the improvement.

Today though, I thought I'd try going up a very slight hill. According to Strava, the section of the hill that I stuck to was around 1-8% grade (average around 5%) for 750 meters. I stuck a cadence of around 90 and by the end of that 750 meters, my legs felt like they were going to explode and no matter how much I willed myself, I just couldn't go further.

I know I'm just a beginner, but that still seems really pathetic to me. Does my poor performance on hills mean that I have poor lactic threshold or overall endurance or what? Is it normal for beginners to suck so bad on "easy" hills when they start or do I have extra bad ability on hills? I know that at this stage I shouldn't be focusing too much on specifics and should just be riding more, but I feel like hills really just destroy me so quickly, i can't imagine how I could go on a group ride or anything like that where there are even easy hills.

Also, there was a strong wind on my ride today for the first time and I noticed a massive difference when riding into the wind. I know it's obviously harder to ride into the wind, but it just felt SO much harder... like i had to really really push/pull my pedals and my legs were burning even at a high cadence at a slower speed (around 18km/hr). Will being on a road bike instead of a mountain bike help a lot with this or is it just a slight improvement?

Thanks again for any insight that you can all provide.