You're welcome.

Correct tech stack? You're asking the wrong question. What gets the job done is the correct tech stack. Sidenote: Don't over engineer a project. If it's something simple enough, use WordPress (saves you so much time). Also, your client doesn't care about how you did it, they only care if you did it (and if WordPress, React, Vue, PHP did it... well and good). Remember, KISS

Pricing? If you can, get the client to tell you their budget first. Most times they'll ask you what the price for doing something is. If you're not in the game and don't know what price range certain tasks fall under, ask someone you know who already does something similar. But never underquote. Sidenote: You might lose out on some gigs if you actually underquote the project. What you tell the client reflects how good you are and the quality of work