I don’t know what the set up is like on a Camry, but if you are interested in getting more involved in your own car repairs I can think of worse things to start on. What you want is a repair manual - most any auto parts store (especially the large chains) carry the Haynes line which are fine. One of these will run you only $20 and if you plan to try to keep the car going for a while I’d argue that its a worthwhile purchase even if you never fix anything yourself. Information alone is often worth its weight. (You’ll probably make back your $20 the first time you need to replace a couple of bulbs).
You can also easily price the parts online and at least find out what your approximate parts cost would be. For the charcoal canister you might check salvage yards instead of new parts. Then if you buy a manual you can check out the procedure and decide whether or not you’re up to it.
Do you know how the mechanic arrived at the canister and valve? What were your symptoms? Evap system codes seem to produce an awful lot of repairs with recurring codes due to guessing. (e.g. pay attn to the post from hd72mm) If I were you I’d start by carefully checking all of the vacuum lines in the evap system and replace the valve first - unless the canister reeks of gasoline.
And stop topping off your gas tank. Just fill it until it clicks off the first time and then leave it alone.