Hello and welcome to the forum. Firstly, don't be nervous about attending any HFT shoots as you'll find the people very friendly and supportive. Don't fret about being the lowest score as somone has to come last and you will soon learn enough so that you can drag yourself a few rungs higher, in fact that's what it's all about. First challenge yourself to achieve a bronze badge...then a silver and then a gold, after that there's no limit
Now , as to scopes....
This is an absolute minefield as both scopes you mention will do the business for HFT. There are some on the circuit that love the Hawke TAC 10x42 but i found it gave me too much parallax error and made me miss closer, reduced kill size targets. I personally use the MTC viper 10x44 and love it but many other shooters just can't get on with it.
The best advice is to pop along to a local club that has HFT shooters and ask to try as many scopes as possible as one that might suit someone else wouldn't be good for you. In a perfect world you should buy both scopes second hand and have a go with both on a proper HFT course as then you'll see the pro's and cons of both scopes in the 'real world'.
There is a HFT shoot at Worcester air rifles this Sunday...why dont you pop along with the family and see what it's all about. I'm shooting the first session but if you fancy going just drop me a message and i'll introduce you to some very friendly people.