If your hair is in great condition and not naturally porous, a semi permanent simply is unlikely to take, there is no way for the colour to get through the water resistant fatty f-layer nor under the cuticle and no space inside the hair for the colour molecules to lodge themselves. You certainly cannot lighten with a semi permanent as you have already been advised, you can only deposit a darker or similar shade.
If your hair is currently sun lightened then it is damaged, a semi permanent may take to those areas but again won't lighten just slightly change the tone. Shampoos containing SLS also damage the hair over time as does brushing and combing and even cotton pillowcases, however gentle you are. Even virgin hair has little to no fatty f-layer and little to no cuticle after a few years of growth.
You cannot purchase 100% hydrogen peroxide AFAIK
but perhaps someone in your country will advise, nor would hydrogen peroxide alone easily lift your hair. Even box dyes have you mixing two bottles of chemical to create a reaction, the mixture is highly alkaline and this alone is also damaging but it's necessary to raise the cuticle and allow the bleach to penetrate.
At it's most basic any lifting home or salon is a mixture of persulphate bleach and peroxide developer. The amount of each used, the concentration (in the UK sold as 10 vol, 20 vol, 30 vol, 40 vol), the amount of heat used and the timeframe dictates how harsh the product is, how much damage it does.
Occasionally you can find acid based permanent dyes which again are supposed to be slightly gentler. Overall it is the formula that make a product gentler or harsher and of course the skill of application - knowing which areas to apply to first and which last - not home or salon products as such. Home wise ammonia free is supposed to be the gentlest but hey don't always 'take' as well, I use Garnier Nutrisse Radiant Blondes which is also sulphate surfactant free.
Another way of lifting the whole head in a slow and controlled manner is a 'soap cap' which is basically a persulphate/ peroxide mix heavily diluted with shampoo. Personally I wouldn't do it since shampoo damages/ irritates my skin but I can see how it is easier on the hair for newbies.
Again, strand tests and coconut oil.