Well you can take a lower end camera and use quality lenses on them and get better shots than the other way around that's why I asked I also have the 18-55mm vrii and the 55-200mm vrii and the lens you are working with the 70-300mm attached to my Nikon D5500 like you I just started shooting and made adjustments along the way. I started in manual mode and just figured it out that way however when trying to shoot action I will shoot in shutter priority trying to get that shot of contact at the plate or that play at second anyway its been fun along the way learning all the different things that make the shot look good and some of my best shots are an accident lol but whatever it works.
Ima geek for this topic. You're totally right about that Westler. The sensors in the more costly newer cameras are faster and crisper. And if you can part with what feels like more $ than you should at the time, long after the cost is forgotten, the quality will be remembered (ahem, at least I tell myself that). If I had $10 to spend, I'd put $6.50 into the lens. I've had some professional photographers tell me "it's all about the glass". I finally invested in a better camera and lenses about 2 years ago and then schooled myself in shooting by reading lots of photographer's how-to blogs + listening to podcasts and it upped my game a lot.
Here's a tip I found, if you live near Cincinnati, CBus or Cleveland, go to Dodd Camera and rent a lens for the weekend. If you rent on a Friday afternoon, you can keep it out for the whole weekend but only get charged for a day. If you want to try a higher end camera and lens, it's really not that costly to get amazing shots of your kid that you'll keep forever. I've rented some pretty kickass lenses for like $30-40 for the weekend. I've even recently taken to renting specific lenses for vacations. I just had a great lens out for about a week for about $100, which would have cost around $1500-ish if I bought it new.
Then, if you shoot RAW format and use Adobe Lightroom or even Photoshop to process, you'll be amazed at what you can do with the photos.
