Check for background applications and see if any are misbehaving or using a lot of cpu.
lowering your resolution will help a bit too.
Disabling fullscreen optimizations works for a few extra fps in the compatibility tab of hl2.exe
No hats / cleantf2 can boost your fps too
Might be useful to know what frequency your GPU and CPU is when running tf2 use something like hwinfo64 and look at limit reasons for cpu/gpu. You may be power throttling instead of thermal.
You can try reinstalling windows, that might help.
If your ram isnt soldered, you can buy another stick of DDR3 for dual channel mode which can boost performance a lot if you're comfortable opening up your laptop and putting another stick in. Check with your laptop model if you can add another stick of ram in and what type you need.
If you are truly desperate (dont do this unless you know for sure what you are doing) but there was some old broadwell microcode that allowed you to set your cpu multiplier to any amount, allowing you to overclock your CPU. Don't do this unless you know exactly what you are getting yourself into. I dont know where this is and i suggest not doing it because you need extra cooling and it might reduce your laptops battery life.
Your pc is weak. It is a dual core with hyperthreading from 2015 with a max boost of 2.7GHz with probably stock speeds/timings on your RAM. If none of these work consider upgrading your pc. Hope something works out for you.