Hello SCD, Good to hear that you are at least trying to shoot in manual. It can be frustrating when you have to make adjustments and the subject like pets and kids are moving about. You’ll get the hang of it, it just takes time and knowing your camera. Soon enough you will be making your adjustments without even thinking about it.
Good to come here or other places for critique and get good honest hard feedback and not the typical fluff that family members give you. It’s nice that they support you, but unless one of them is an established photographer, what do they know, right?
Anyway, a lot of your pet photos are nice and sharp, I would try mixing up the poses somewhat, too many of the same frontal profile, but they are nice.
The landscaping ones are nice. The mountain scene, I hope you don’t mind, I took a slight liberty and made a super slight adjustment to it HERE.
I straightened it, lowered the exposure, raised the temperature [I forgot to look at what degree] and added a touch of contrast to it, that is all. All done in ACR, from a screenshot.
The buildings from Central Park. You will always have the leaning issue when shooting buildings unless you use a tilt-shift or adjust the perspective in post or shoot from a different angle. It is just an effect that you get due to the focal plane angle in relation to the buildings. An interesting article, if you are really interested, here.
I would not run out to go buy a tilt-shift, they are rather pricey. I have one and rarely ever use it, but it is nice when it calls for it.
As you can see here, I adjusted the perspective in post, but it crops out quit a bit.
You can always try local groups for more hand-on experience, try some sites like Meetup, there are several people that charge for hands-on tutoring and then some that welcome newbies to their group.
As for your friend and their engagement. Just take your time, focus and make sure that your subjects eyes are in focus, try not to shoot at un-flattering angles like from above or below, unless it is for some sort of effect. If you are shooting outside, use the sun to your advantage. Never place your subject directly in the sun were they are blinded and squinting. If you don’t have a flash, try using a reflector, if you don’t have one of those, try a piece of posterboard, maybe paint one side silver or gold. Silver adds more light, gold adds a little more light and warmth.
A trick I learned many years ago and I will share with you, don’t tell anyone! If you can’t get willing subjects to shoot and you want to get out there and do some test shooting, get yourself a cosmetology practice head and stick it on a tripod. Gives you a subject with skin tone that does not complain.