Mobile application support. How to start understanding?

Question

Mobile development

There is an application for ordering food delivery to your home. The project was originally built as a franchise, I bought a ready-made application from the developer, he made a website for me, provided technical support, and I, in turn, found clients, scored organizations through my personal account. Further, the developer, in view of some reasons, announced the termination of support for the software and undertook to transfer the source code and infrastructure to me. According to the infrastructure, I either do the transfer myself to my server, or by the developer for ***** rubles. Or he provides a customized infrastructure and provides technical support for the software, but for a much larger amount than before. The question is. There is a desire to lead the project yourself, since the second option is expensive, but knowledge is minimal, so where to start and what to look for in Google, to at least just move the infrastructure? In the future, I plan to provide technical support for the application myself, is it possible with the help of one person? If possible, briefly what the mobile application, website, servers, how they are connected, etc. consists of. etc.?

Answer 1

I think you see too many options. In fact, you have only two of them:
Buy the project from the developer and transfer it to your infrastructure by his forces. And then:
1) either use his technical support
2) or hire a third-party person to provide support.
You don’t need to go where you don’t have qualifications. Do what you do best and have a qualification: sales.
Yes, you can try to do everything on your own, but then when you try, you will still return to the two options that I described :)

Answer 2

1. You need to find out the language in which the application is written
2. Find out the language in which the server part is written
3. Request documentation, but it is most likely not available
4. Learn the necessary programming languages
​​5. Understand the features of the server part as a system administrator
In such cases, usually hire a person. Well, or like in the state remotely.

Answer 3

Server OS: Ubuntu. The server uses the LAMP stack (linux, apache, MySQL, PHP). PHP module configuration: bcmath, calendar, ctype, curl, date, dom, exif, fileinfo, filter, ftp, gd, gettext, hash, iconv, imagick, imap, intl, json, ldap, libxml, mbstring, mcrypt, mysqli , mysqlnd, openssl, pcre, PDO, pdo_mysql, pdo_sqlite, Phar, posix, pspell, readline, Reflection, session, shmop, SimpleXML, soap, sockets, SPL, sqlite3, standard, sysvmsg, sysvsem, sysvshm, tokenizer, wddx, xml , xmlreader, xmlwriter, xsl, zip, zlib