Don't know much atall about welders, I've only been using a large arc welder for about 4 years the odd time, so I will give my 2cents on the arc welder only.
I've just bought a wee 50 euros Parkside arc welder only the other day, its pretty much the size of a car battery with leads, space is valuable in my workshop, hence a want for a welder of some sort.
Can't say its any good yet, but I won't need it for big jobs, as I have a 16amp required 250 amp one at the folks.
I need a welder here for some tablesaw restoration work, some machine bases, aswell as some smaller toolmaking things at the moment.
A good non critical thing to get started might be something like shelving or machine bases of some sort, get some 50x50x5 angle iron and some suitably sized pipe or box section and have at it.
The thing with welding is you can always add the metal back again, so it might take you a while melting away your work or grinding it back, but you know you will get there for sure, and when welding anything in the home shop, it will be welded all over with juicy welds, and not cheaply tacked like what you see in industry, so everything always turns out way over built.
Looked at some used machines online to compare for what's a better deal, and they are very very cheap,
like 30 quid used for a 170 amp arc welder, the rod clamps and earth clamps less than a fiver in the local agri shop, black glass 2 quid, (I put a sodabottle thin plastic screen over it, to stop it getting scratched) about a tenner for a box of 3.2mm rods that will see you through a good few projects.
The 170 amp ones look good value, are 13amp, have a variable crank adjustment, rather than a low/high pretend winder switch, probably can weld your common 4 or 5mm steel with patience, have a cooling fan and the 3.2mm rods are cheaper than thinner ones.
It says that 2.5 is the max for my new machine, max 100 amps, restically 80.... hoping this is not over exaggerated claims like with all tools you get.
If I had the space, I would have went the secondhand route.
Clothing wise I find the angle grinding to be worse, and I would love if I got around to making an leather apron.
An auld hat.
Some earmuffs.
Get two pairs of safety glasses for good measure! and wear a pair all the time throughout the session till metal is cold, because the slag pops the weld off whilst cooling.
and keep those boots tight
Tool wise
I use a small bench grinder, some long masonry nails for making picks for slag, and the grinder amongst other things to keep those picks sharp, keep the mouth shut and watch your teeth because those steel nails will recoil like a bullet!
Little poundshop cross pein hammer.
Wire brush.
One absolutely essential tool, actually tools is a pair of 4.5 " angle grinders.
Source the cheapest 1mm thin cutting discs you can find, if you get thicker cutting discs than that, you will pollute yourself with dust, while it's also a lot harder work for the grinder to do.
The grinding discs you can get some mileage on them, you wouldn't search the internet for them, but compared to the ultra consumable thin cutting discs, is ok to grumpily pay 2 or 3 bob for them locally.
The automotive store is the best value for the 1mm thin discs singularly, as there are no pound shops with 5 packs close.
Don't go to the likes of homebase for these things, you will pay 6 or 7 times the cost of discs in these large home/diy outfits.
To sum it up
What supply have you got?
Have you got space for a larger one?
What work are you doing?
Good luck
Tom
