It is pretty common to have a very slight difference in neck relief curve from one side of the neck to the other. Unless the neck is quarter sawn (rare indeed on a budget guitar though sometimes you can get lucky), then the neck is likely to twist very slightly as it ages. As long as the high E side has just a bit less bow in it than the low E side, you can normally live with a slightly higher action on the low strings. Very few necks are perfectly straight or have exactly the same relief bow on both sides. Even high-end guitars can have different curves - I've got a Rickenbacker in for fettling at the moment that has a significantly different relief curves that even the double truss rods can't fix (they probably could if they were dual-action truss rods, but they aren't).
This is where fret levelling/dressing can come in as whilst the fretboard may not be perfect, you can adjust the relative fret heights to counter a lot of that, as it's the top of the frets themselves that really determine the playability of the guitar.
It really isn't hard to do it yourself. I've seen a lot of first-time guitar kit builders do it very successfully. You need a notched straight edge (Amazon or eBay) as you need to set the fretboard as flat as you can first, which a straight edge on the top of the frets won't tell you, so you need a straight edge with notches cut in for the frets. E.g. https://www.amazon.co.uk/Leezo-Stainles ... 159&sr=8-7
You'll need either a straight-edged piece/beam of wood or metal that you can double side tape some P240 paper to, or else a radius block to match the radius of the fretboard (probably 9.5" for the Squier Tele, though it may well be 12" as that's a favourite for Chinese guitars) Check on the Squier website for the model year specs. Something around 12" -14" long is ideal.
Then some masking tape, to tape up the board between the frets, a black permanent marker pen e.g. Sharpie, and a range of sandpaper grits from P240 upwards, to as fine as you can get (I use micromesh cloth for the really fine stuff).
You'll definitely need a fret crowning file of some sort. I use the ones with a curve built-in. I have got some flat triangular files with safe edges but find the rounded files a lot easier. One with a 2.5mm width should fit most standard electric guitar frets. I have one of these (amongst others) which works well and isn't that expensive. https://tonetechluthiersupplies.co.uk/f ... adius.html
The cheap orange-handled ones on Amazon/eBay do work but they are better for wide and high jumbo frets as they have a very large radius curve and start hitting the top of the fret before the sides are properly profiled on medium width frets.
Once the board is set flat (using the notched edge and the truss rod), it's then a matter of taping up the board, putting black marker on the top of the frets, running the small beam over the frets from end to end of the neck until all the black marker is off the top of the frets. High fret/fret areas get sanded down first, so you may end up with a low fret in between two higher frets that takes a while to reach.
Then put black marker on the top of the frets again, and run the fret profiling file along the length of the fret until you have just a very thin line of black left along the top of each fret.
Check the frets for any sharp ends. I use a flat needle file at a 45° angle to smooth these off. If the fret ends are sitting proud of the board (which can happen if the wood's shrunk), then file the ends flat first before filing at 45°.
Then it's just a process of sanding the frets to remove filing marks and then polish them smooth. I start with P240, which does most of the work, and then run up to really fine grits and finish off with a rub with metal polish.
Remove the masking tape and you're good to go.
What you ideally want to get want are some nut files, as taking the nut slots down below the factory setting can really make the guitar easier to play as well as making the intonation better and lowering the overall action. But good ones aren't cheap. This about the cheapest good set I've come across: https://www.northwestguitars.co.uk/blac ... -10-gauge/
You can get less specific gauge sets with more files in, but a set for 10s will happily do 9s (though if you only use 9s then you can get a set just for those).
Along with a good set of Allen keys, some good quality small to medium flat and cross-head screwdrivers, and 10, 11, 12 and 13mm spanners, those should be the tools you really need to cope with setting up most guitars.