Mountain Bike Forums

Hi all,
Ok i have built a bike with the help of a friend but have now been bitten by the bug and want to upgrade but dont know really where to start. for the last few months ive been doing about 15 miles a week, mainly on road but off-road cross country when i get to tracks. now i usually have my baby girl on here rear seat but do go with friends alone. here is the spec of my current ride.
carerra kracken se frame
shimano hyperdrive crank
shimano acera x front der
shimano deore rear mech
richie bar
fsa headset
shimano cassette
rst t8 launch forks
shimano all in one brakes and shifters
shimano front disc and cal
cant remeber rear make but it is rubbing badly.
question is where do i start and what to get?? do i get a frame and buy stuff seperately gradually while i still ride mine or do i buy stuff and keep swapping bits from my current ride?? do i need light weight stuff ie carbon fibre?? i have no idea what stuff to get as there is so so much and makes?? I know this is a lot to ask but if anyone can help me it would be great. i def want to self build but need some guidance on gear and the way to build. budget wise, im a good saver and can wait for good stuff but not paying 1000’s for each item
Thanks in advance for any help, Tony