well the wedding is probably the cheapest we got married and had a honeymoon for about 2k including a dress made by a dressmaker we had 30 guests you could have a nice wedding for not that much
children do not have to cost a lot in terms of equipment and stuff in the early years, it is childcare that costs a lot and can take up a large proportion of salary it gets better once they are 3 and get some free hours however once childcare costs go down clothes and tech and clubs go up in cost
I bought a house years ago but first in Midlands and then in Scotland so house prices are not crazy multiples of average salary I had a good job but all the money was mine I had no help from parents or inheritance though my parents helped put flat pack furniture together they were never in a place to help financially,, I saved really hard second hand furniture no going out to restaurants except birthdays takeaway coffee wasn't a thing then etc to start with
My husband has never been paid more than average often less but he managed to save over 50K by the time we married ( he was in his 40's) he says he just saved all the money he never spent smoking drinking and gambling it was easy even in 1990's to spend 25-30 pounds a week on these and it starts to add up. He is still frugal apart from crisps!!
However I do realise that saving £50 a week £2600 a year ( allowing for inflation) won't go far in the southeast or London, but where we are in Scotland an ex council house with 3 beds and a garden is 75-85K depending on decor etc so here saving for 3 years would get you a 10% deposit
you can save £50+ a week by making your own lunches, not buying coffee out, using a SIM only phone deal; don't update tech when existing stuff still works, switching utilities, using freeview not Sky or netflix, walking or running instead of the gym, cutting down severely on presents holidays and going out, shopping at Aldi; not buying anything you don't need especially more clothes, make up etc
you can't however save £200 a week like this which is what is required near London and the SE
consider buying a house a bit further out in less fashionable area that needs basic work ( not new CH / rewiring / new roof) that you can take your time with, I had deckchairs in my living room for 4 months when I got my first house you can actually live with an avocado bathroom so long as it doesn't leak and old fashioned carpets, kitchens etc