Congrats on getting your own land!

My recommendation would be to look into permitted development rights for agricultural land and see if you are over the threshold in size.
https://www.gov.uk/planning-permissions-for-farms/permitted-developmentWith large sizes, you can create fences, walls, entrances all under PD, but also more importantly, agricultural buildings without needed permission.
But I would also inform the local authority about what you are doing anyway - there's a specific form for that, but it's more of an keep them informed rather than request permission.
I would plan out your farm and what animals you will keep if any and talk to a planning consultant just to bounce it off them.
I'd then build your barns where you'd imagine a house could go in 10 years time.
This is a very simplified overview, but one strategy is to do a conversion after 10 years of it being a barn. You may never use it, but it's a nice to have and will help with increasing the value of your land.
10 years of having a large enough barn anyway lends itself as an incredibly useful space for farming or a workshop.
You could also buy some glamping tents and look into putting them on AirBnB if it's less than 28 days a year.
Good luck!