Customize WordPress theme and add specific functionalities

I need to create a wedding planner app. I am using a directory listing WordPress theme and i have some features that help my idea but i don't have others. So the features i already have is: 1- Directory listing with all kind of filtration. 2- Front end listing submission they can add listing from the front end. 3- Dashboard for each users and have the ability to control them listings and track insights. 4- Each user have the section in its dashboard to add favorite listings. 5- Internal ads each user can promote its listing. 6- Review system. 7- Each vendor user can sell product through mutli vendor feature. What i need to add is: 1- i want a way to make each user add their wedding date after register. 2- i want a way to make each user add their wedding budget, Bride name and groom name. 3- I want for each user a wedding dashboard that contains: a- First page show countdown for wedding date, Show the starting wedding budget and the actual spent and the difference between them and welcome message for the groom and bride with names and unfinished tasks insights number of invitation sent. b- internal sections one for a budget planner ( i will explain later), To do list, Guest manager with Invitation list using emails. Explanation: --- Budget planner is: Like a table that can add to it a category like ( Venue, Catering, makeup artist, etc..) and assign to each category in another cell a vendor which the user will choose by typing the name of the vendor already in the app listing using ajax search and it show for the user and select it. Then type estimated cost for the services in another cell then type the actual cost in another cell. And in the bottom of each cell it give the user the total of the estimated cost cell and the total of the actual cost cell then at the main dashboard it show the actual budget and the actual spending by subtract the total of actual cost from the starting budget. --- To do list: User can add a tasks and it contains a title a date estimated to finish and a button to click to say it is finished. And show a progress bar to the finish tasks and unfinished tasks with numbers. --- Guest manager: User can create groups like ( Bridal family, Grooms family, etc...) and add a full contact( Name, Email, Phone, Address, etc..) and can add note about it and choose the age from three options ( child, baby,adult) and for each of them can assign the the invitation sent or not. And can send an email by filling a form and have a specific theme ( I think we can use a plugin for that just we will need an integration). Here is a web app look like it you can register with facebook to take a look as a user. It is more complicated than what i want but just take a general l look and came back to what i ask for. [login to view URL] And this my website: [login to view URL] My website is connected to a react native app and the developers using vue.js i just want the new features compatible with the app. Here is the theme i use: [login to view URL] The online Docs: [login to view URL]