First:to make projects just build things on creative or servivle (What ever suits you best) use F2 to take screen shots but i wude recommend doing it with F1 first so noone sees your HP bar/experanceBar/foodbar and all that.Second:to make skins go to www.minecraft.net and log in to your profile,next click on Profile tab,then it will sat "Change your skin?" "Start with refrence skin" click on "Start with refrence skin" and then download that,i wude make a folder in your pictures called Skins if i make a lot of skins and i do,then use a painting program or use the one built into your computer to change the skin desine how ever you want.Third:For Texturepack you need the refrence Texturepack and for that you can find it some where by doing www.google.com and typeing in the serch Minecraft Origanal Texturepack and find it , then unzip it (You will need 7-zip or winraw to Zip it back up) then use a painting program or the origanl painting program in your computer.Fourth:I have no idea how to make mods you need to ask good modders or nick how to make mods.Fifth:To make it to where people cna download your worlds or mods you need a zipping program i use 7-zip so i wude get that,then zip the world you make for the people to see your projects,and for mods or textures too,use a free file thing like www.mediafire.com to let people download it you can even make a nother link that is connected to www.adfly.com to send you money somehow (idk how to do that but i think free is better) and then you can skip the ad to send people to www.mediafire.com to get the mod/texturepack download.

Thats all i know i hope this helped o_o...