Bought my 1997 from my brother in law who is a 240sx guy. Got the car in a Rb25 trade and sold it to me for $800. Little rusty. Interior is loose in almost all areas. Fender replaced. Door replaced. Windows off center on both windows. One is power and one is crank. All mix matching paint from new door and fender. Needs paint. Ugly chrome rims gotta go. Straight piped it with eBay muffler and pieced together an intake for now since it had none at all. Battery is too tall so one of the terminals has grocery bags and zip ties so it doesn't touch under the hood and shock the shit out of me.. many many more issues.. but I love it and it will be a fun project for over the years. Let me know what you would do first, I have a long way to go and not much money hahaha.

Also the hood was popped, it does not actually have that gap like that.

I would do all necessary maintenance before anything. Plugs, all fluids, timing belt job, (can almost never trust how recently it's been done or if correct.) And any other necessary items to get it to be as reliable of a dd as possible, before even thinking about any mods. Unless you plan on tearing it all the way down and starting from there.

I'd fix your battery issue first. Insulate it with a rubber or plastic covering. Electrical tape works. Scrape off that lie of a sticker...hahaha! Then get to cleaning up your engine. A clean engine makes it way easier to see everything that's going on and you don't get as much grease on you. Then do the regular maintenance like Froggy said.

Looks like a fun thing, good luck making her pretty again!

Welcome - your first step should be to read through several of the pages linked in the Resources tab in the navigation. The Maintenance guide is a must read, as well as the upgrade paths and FAQs. Then go through the Tech Articles to find out how to do what needs to be done. Then, once you've read through all of that, post questions in the appropriate forum about what you need clarification on.

Again, welcome!

I second the advice already given here. Get the car running reliably in STOCK FORM first. And then leave it that way for a little bit till you're completely familiar with what you have. Then, and only then, determine the direction you want to go with the car and enjoy the process along the way.