If you have DSMLink you should have a USB to OBD1 cable to connect to your ECU.
From what I see under the hood it should be set up for run in Speed Density mode and will likely have upgraded injectors to support the aftermarket turbo, so recovering the current tune will be much more important than a baseline for a stock engine.

Once you have the DSMLink client software installed you should take a log and save it. It will contain the current settings and serve as a backup against future changes as you learn how to tune via DSMLink.

I will have to purchase the cable and software as I didn't get it with the car unfortunately. I can get an exact mod list but I know its a built head with an upgraded cam.

Do you think tuning it myself is do-able, or should I continue to look for a tuner?

Its a long story about how I got the car but it was built and sold by owner #1, with out a tune (allegedly)
Owner #2 didn't drive it and sold it to me. I didn't have the history on the car so I drove it home and got into contact with owner #1 and haven't driven it since.

This is the only video I got of it running before I parked it.

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How much do you know about tuning in general?
How much do you know about Galant VR4s?

Before you start buying anything take an inventory. There is a bunch of stuff I can see right off the bat and there there are things that will need to be taken apart to be sure of like the ECU. You'll need to pull it and open the cover to make sure it is and EPROM ECU with a red ECMLink V3 chip in the EPROM socket. If it does you can order a 1G V3 cable and download the latest client software. If it doesn't it will depend on what you find.

Offhand I can see a MSD DIS-2 Plus CDI driving a Coil on Plug ignition, An AEM Fuel Rail and aftermarket fuel pressure regulator that seems to be missing it's manifold pressure reference hose and needs s better mounting solution. What looks like a JMF STREET 1G intake manifold with an S90 type throttle body. A Forced Performance exhaust manifold and likely one their turbos with a TiAL wastegate. No MAF that I can see before or after the vented BOV. I also can't see the Intake air temp sensor (IAT) or the MAP sensor that would be needed to run Speed Density. The PVC system has been removed and running a vented catch can for crankcase pressure.

Given the SMIM, the turbo and other parts it's likely you have cams (as you expect) and injectors (I don't see the injector resistor pack so perhaps high impedance injectors) along with other engine mods that will be much harder to identify without a teardown.

Do you know what fuel it's using?

I've never tuned before, I understand the basics but have never actually messed with anything, especially obd1. Definitely outta my depth on this car for sure but this is where im starting I guess

I will reach out to the owner who built it and see if he has a full mod list. As far as engine goes, when I talked on the phone he said it was a refreshed stock bottom end (same clearances, rods, and pistons) and a built head. I'm assuming I would need to know cam lobe height to account for it in tuning as well as valve spring recoil force.

As far as I'm aware, the car is set up for street gas (91). I did notice the fuel pressure regulator is missing any sort of boost or air reference and there are some things that don't make a lotta sense with the boost control I'll need to look into. The IAT sensor is tucked just before the throttle body on the back side but isn't optimal with the battery location so I need to weld in a new bung. As far as MAF or MAP sensors, I haven't seen any.

When I get some free time I'll get into the ECU and see whats actually installed as well as do some research on the injectors and figure out the fueling situation. It looks like most the things needed are here and the owner sold it before getting it completely ready so I'm coming in at half time and don't even know what game I'm playing

Yep, I'm suggesting you figure out the game before starting the second half.