Please help with your opinion

I'm currently slowly upgrading my system and would appreciate your opinion. Here is what I'm currently using...

music hall 2.1 (clearaudio Aurum Alpha cart)
Rega RS3 speakers (first upgrade)
Yamaha A-500 amp (early 80's)

Should I upgrade my TT to a Rega P5 or purchase a Jolida Tube amp. I intend to upgrade both but which would you purchase first. Thank you very for your opinion and help!

I'd go with the (integrated) amp first. The caps on the Yamaha are nearing the end of their useful like, and many of the early 80's amps from Yamaha and others had VERY low THD specs through the use of lots of negative feedback. A modern tube amp will sound VERY different and likely very much better. Make sure what you get has a phono stage unless you intend to buy a separate one. A lot of modern equipment in line stage only.
i would go to the amp first....if you are wanting tubes , then by all means go with them, but what is wrong with rega gear? the rega speakers will perform well with the ss rega ...i i believe the rega sounds as close to tubes as most ss gear.....are you going to get and int. jolida? or just a tube amp?
I've got a great deal on three new tube amplifiers (one, a Hybrid and two are Tube Integrated with a remotes, two models under $500.00), which is the route I would suggest you take. The source turntable you have could benefit from some upgrades that you could do for a pittance to upgrade it's sound or performance. But the amplifier being the heart of your system should be your first priority. While Jolida does make some really nice stuff there are better deals on better performing equipment. Just check out all the used Jolida gear, there is a ton. For me, I judge how good a component is by how long I want to keep it before feeling the need to upgrade. It seems to me Jolida buyers are never happy with what they got and want to pass it off to someone else. While there are so many manufacturers of tube amps that put Phono stages in the components they sell, usually the Phono stage is inferior and warrants the use of a separate phono stage. There is one model Preamp that makes an excellent Phono stage that is built in and battery powered. It was made by Golden Tube Audio but I can't remember the model number. And you would still need a main amplifier. Perhaps use the Phono section in your current amplifier alone with your new amp until you can save enough to get one that fits in with your gear and satisfies your tastes. Hope this helps, and feel free to contact me to discuss my tube amps and whether they might be a good fit for you.
I'm generally not in agreement that your amp is near the end of its life. I have two Yamaha amps from that period and they are both out-to-equally performing in comparison to some of the much newer and more expensive amps I've had chance to hear. The older Yamahas were built very good, and, they had rather good phono capabilities.

An upgrade to a good used Music Hall 7 or one of the lower end SOTAs could be worth exploring.
I would second the turntable upgrade first - I went with the P5 myself, and am very happy with it. It will be a very big improvement on your Music Hall, I have had both of those tables in my system - better soundstaging and imaging, and better resolution of instrumental and vocal timbres. However, I would never argue against someone wanting to move to tubes, either, though I have not heard the Jolida's in particular.
if your associated equipment is not up to date enough to hear source upgrades then you are wasting your money.....the source can't be heard correctly if you can't hear it through the gear you are using and you can't hear small detailed differences until you have a good detailed amp....