I have 8 APPS installed and deleted 5, Then choose a new paid theme, will I have residual code?

[simplynootropic]

I want to know if I have 8 APPS and have deleted 5 irrelevant ones

I am building a new store, and this account has been a development server to test APPs and load content in.

If I load in my new theme, will that theme integrate with my 8 current apps? Or will there be residual code from the old 5 ones I deleted still even If I change themes?

Example:

I had stamped.io first

I've changed to yotpo

I am now buying prestige theme

Should I start again on new development server or is this server fine if I install a new theme?

Thanks! I want my new website to be clean and fast without old code!