hi there Dixie Lee, nice to see you post in here again! looks like you're all set up to have some great fun with that camera and what a start! i too very much like the bike shot. it's unique. i've never seen that before. hope your dad doesn't tell you off for riding without holding onto the handle bars! lol oh... hopefully you also have a neck strap for your camera too!
okay you want some critique... let's see if i can give you something to look at.
image #1 - i like it very much. you haven't got your main subject centered and that means there's a little more interest in the photo. i have two suggestions for improvement... a) there is a little bit of blurring. when taking the shot, try to click the shutter button as you breathe slowly outward. that might help to keep your camera still. b) if the sun was behind a larger branch or tree, would the effect look better or worse? that might be something you can try, just to see the difference.
image #2 - a slight blurring here too... i'm not sure if post processing using a sharpening adjustment would help. maybe you could try it and see. i love the name of the tree. it makes my muse start dancing and my fingertips itch to write.

in fact, i think the slight blur actually enhances the feeling of the 'spirit' tree.
image #3 - very sharp and clear image of the STOP sign. to improve, i would think about trying to get the whole of the sign in the image, a little bit is missing from the top. and i would try to make sure it was straight as it is close to the edges of the photo. i like the background of the tree... looks like a neat place to picnic!
image #4 - i love black and white and i love this image. to improve hmm... let me think... maybe if you stepped back a little bit you would have the whole tree in the photo? and in an image with solid straight lines it is especially important to make sure the horizontal lines are straight. these are only very slightly higher at the right side of the image. (does your camera have a 'grid' that you can turn on? i sometimes have mine turned on and it can help when i'm taking photos of subjects with lots of straight lines, eg buildings, or the sea horizon etc.)
image #5 - hmm only thing i can think of to improve this is to print it and frame it on your bedroom wall.

and get your mum to make sure there's bandages in the first aid kit in case you fall off your bike next time you do it. lol
i hope something in here is helpful to you.

like the others have said, keep taking photos, feel free to come in and share them here and to ask any questions.
thanks for sharing these photos... i always learn a lot when i look closely at images to critique, so thank you for that too.
rosesm